Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Tests
Refer to appropriate SYSTEM WIRING DIAGRAMS article, Transmission Controls for schematic and connector information.
Refer to appropriate SYSTEM WIRING DIAGRAMS article, Shift Interlock for schematic and connector information.
PINPOINT TEST A: THE BRAKE SHIFT INTERLOCK SYSTEM DOES NOT RELEASE/LOCK CORRECTLY - COLUMN SHIFT
- A1 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Disconnect: Brake Shift Interlock Actuator (BSIA) C2008
- Measure the resistance from BSIA C2008-1, circuit 57 (BK), harness side to ground.
- Is the resistance less than 5 ohms?
- YES : Go to A2.
- NO : REPAIR circuit 57 (BK). RECONNECT all components. TEST the system for normal operation.
- A2 CHECK CIRCUIT 810 (RD/LG) FOR VOLTAGE
- Measure the voltage at BSIA C2008-2, circuit 810 (RD/LG), harness side, while pressing and releasing the brake pedal.
- Is the voltage greater than 10 volts with the brake pedal depressed, and less than 5 volts with it released?
- YES : INSTALL a new BSIA. Refer to Brake Shift Interlock Actuator - Column Shift .
- NO : For voltage less than 5 volts, go to A3.
- For voltage more than 10 volts, go to A5.
- A3 CHECK CIRCUIT 810 (RD/LG) FOR AN OPEN
- Disconnect: Lighting Control Module (LCM) C2145a
- Measure the resistance between BSIA C2008-2, circuit 810 (RD/LG), harness side, and LCM C2145a-6, circuit 810 (RD/LG), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to A4.
- NO : REPAIR circuit 810 (RD/LG). RECONNECT all components. TEST the system for normal operation.
- A4 CHECK CIRCUIT 810 (RD/LG) FOR A SHORT TO GROUND
- Measure the resistance between BSIA C2008-2, circuit 810 (RD/LG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to A7.
- NO : REPAIR circuit 810 (RD/LG). RECONNECT all components. TEST the system for normal operation.
- A5 CHECK CIRCUIT 810 (RD/LG) FOR A SHORT TO VOLTAGE
- Disconnect: LCM C2145b
- Measure the voltage at BSIA C2008-2, circuit 810 (RD/LG), harness side.
- Is the voltage greater than 10 volts?
- A6 CHECK CIRCUIT 810 (RD/LG) FOR A SHORT TO VOLTAGE
- Disconnect: LCM C2145a
- Measure the voltage at BSIA C2008-2, circuit 810 (RD/LG), harness side.
- Is the voltage greater than 10 volts?
- YES : REPAIR circuit 810 (RD/LG). RECONNECT all components. TEST the system for normal operation.
- NO : INSTALL a new LCM. RECONNECT all components. TEST the system for normal operation.
- A7 CHECK FOR LCM BRAKE INPUT VOLTAGE
- Measure the voltage at LCM C2145b-5 while pressing and releasing the brake pedal.
- Is the voltage greater than 10 volts with the brake pedal depressed, and less than 5 volts with it released?
- A8 CHECK THE BATTERY JUNCTION BOX (BJB) FUSE 14 (20A) INPUT VOLTAGE
- Measure the voltage at the input side of BJB Fuse 14 (20A).
- Is the voltage greater than 10 volts?
- YES : Go to A9.
- NO : INSTALL a new BJB. RECONNECT all components. TEST the system for normal operation.
- A9 CHECK THE BJB FUSE 14 (20A)
- Check fuse: BJB 14 (20A)
- Is the resistance less than 5 ohms?
- A10 CHECK CENTRAL JUNCTION BOX (CJB) FUSE 28 (7.5A)
- Check fuse: CJB 28 (7.5A)
- Is the resistance less than 5 ohms?
- A11 CHECK CIRCUIT 1119 (RD) FOR AN OPEN
- Disconnect: Brake Pedal Position (BPP) Switch C278
- Measure the resistance between the output side of BJB fuse 14 (20A), and BPP switch C278-3, circuit 1119 (RD), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to A12.
- NO : REPAIR circuit 1119 (RD). RECONNECT all components. TEST the system for normal operation.
- A12 CHECK THE BPP SWITCH
- Measure the resistance between the BPP switch pin 3 and pin 4, component side, while pressing and releasing the brake pedal.
- Is the resistance less than 5 ohms with the brake pedal depressed, and greater than 10,000 ohms with it released?
- YES : Go to A13.
- NO : INSTALL a new BPP switch. RECONNECT all components. TEST the system for normal operation.
- A13 CHECK CIRCUIT 511 (LG) FOR AN OPEN
- Remove CJB Fuse 28 (7.5A)
- Measure the resistance between the BPP switch C278-4, harness side, and the input side of CJB fuse 28 (7.5A).
- Is the resistance less than 5 ohms?
- YES : Go to A14.
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- A14 CHECK CIRCUIT 1651 (WH/RD) FOR AN OPEN
- Measure the resistance between the output side of CJB fuse 28 (7.5A), and the LCM C2145b-5, circuit 1651 (WH/RD), harness side.
- Is the resistance less than 5 ohms?
- YES : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
- A15 CHECK CIRCUIT 1119 (RD) FOR A SHORT TO GROUND
- Disconnect: BPP Switch C278
- Remove BJB fuse 14 (20A)
- Measure the resistance between the BPP C278-3, circuit 1119 (RD), harness side and ground, while pressing and releasing the brake pedal.
- Is the resistance always greater than 10,000 ohms?
- A16 CHECK THE BPP
- Measure the resistance between the BPP pins 1 and 4 and pins 2, 3 and 5, component side, while pressing and releasing the brake pedal.
- Is the resistance less than 5 ohms with the brake pedal pressed and greater than 10,000 ohms with it released?
- YES : Go to A17.
- NO : REPLACE the BPP. RECONNECT all components. TEST the system for normal operation.
- A17 CHECK CIRCUIT 511 (LG)
- Remove CJB fuse 28 (7.5A).
- Measure the resistance between the BPP C278-4, circuit 511 (LG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to A18.
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- A18 CHECK CIRCUIT 1651 (WH/RD) FOR A SHORT TO GROUND
- Disconnect: LCM C2145b
- Disconnect: ABS Control Module C135
- Measure the resistance between the output side of CJB fuse 28 (7.5A), circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to A19.
- NO : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
- A19 CHECK ABS MODULE FOR AN INTERNAL SHORT
- Connect: ABS Control Module C135
- Measure the resistance between the output side of CJB fuse 28 (7.5A), circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to A20.
- NO : INSTALL a new ABS module. RECONNECT all components. TEST the system for normal operation.
- A20 CHECK LCM MODULE FOR AN INTERNAL SHORT
- Disconnect: ABS Control Module C135
- Connect: LCM C2145b
- Measure the resistance between the output side of CJB fuse 28 (7.5A), circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- NO : INSTALL a new LCM. RECONNECT all components. TEST the system for normal operation.
- A21 CHECK BSIA VOLTAGE CIRCUITS FOR A SHORT TO POWER
- Remove BJB fuse 14 (20A).
- Measure the voltage at the LCM C2145b-5, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- A22 CHECK BPP SWITCH FOR INTERNAL SHORT
- Measure the resistance between the BPP switch pin 3 and pin 4, component side, with the brake pedal released.
- Is the resistance less than 10,000 ohms?
- YES : INSTALL a new BPP switch. RECONNECT all components. TEST the system for normal operation.
- NO : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- A23 CHECK BSIA VOLTAGE CIRCUITS FOR A SHORT TO POWER
- Remove the CJB fuse 28 (7.5A).
- Measure the voltage at the LCM C2145b-5, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : Go to A24.
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- A24 CHECK ABS MODULE FOR A SHORT TO POWER
- Disconnect: ABS Control Module C135
- Measure the voltage at the LCM C2145b-5, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- NO : INSTALL a new ABS module. RECONNECT all components. TEST the system for normal operation.
- A25 CHECK THE DEACTIVATOR SWITCH
- Disconnect: Deactivator Switch C272
- Measure the resistance between the deactivator switch pin 1 and pin 2, component side, while pressing and releasing the brake pedal.
- Is the resistance less than 5 ohms with the brake pedal depressed, and greater than 10,000 ohms with it released?
- YES : Go to A26.
- NO : INSTALL a new deactivator switch. REINSTALL all components. TEST the system for normal operation.
- A26 CHECK CIRCUIT 636 (OG)
- Disconnect: PCM C175b
- Measure the resistance between the deactivator switch C277-2, circuit 636 (OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : CONNECT PCM C175b, deactivator switch C277 and INSTALL BJB fuse 14 (20A), then depress the brake pedal. If BJB fuse 14 (20A) fails, INSTALL a new PCM.
- NO : REPAIR circuit 636 (RD). REINSTALL all components. TEST the system for normal operation.
PINPOINT TEST B: THE SHIFT CONTROL IS OUT OF CORRECT GEAR RELATIONSHIP - COLUMN SHIFT
- B1 CHECK THE SHIFT CONTROL COMPONENTS FOR DAMAGE
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Gain access to the shift control components.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe all shift control components while moving the selector lever through all gear ranges.
- Are any of the components damaged?
WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in FIRE SUPPRESSION SYSTEM article. Failure to follow the instructions may result in serious personal injury. - B2 CHECK THE SELECTOR LEVER CABLE AND BRACKET INSTALLATION
- Check to make sure the selector lever cable and bracket installation is correct. Refer to Selector Lever Cable and Bracket - Column Shift .
- Is the selector lever cable and bracket installed correctly?
- B3 CHECK THE SELECTOR LEVER CABLE ADJUSTMENT
- Check to make sure the selector lever cable adjustment is correct. Refer to Selector Lever Cable Adjustment - Column Shift .
- Is the selector lever cable adjusted correctly?
- B4 CHECK THE SELECTOR LEVER INDICATOR ADJUSTMENT
- Check to make sure the selector lever indicator adjustment is correct. Refer to Selector Lever Indicator Adjustment .
- Is the selector lever indicator adjusted correctly?
- B5 CHECK THE TRANSMISSION RANGE (TR) SENSOR ADJUSTMENT
- Check to make sure the digital TR sensor adjustment is correct. Refer to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article
- Is the TR sensor adjusted correctly?
- YES : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to B6.
- NO : ADJUST the TR sensor. TEST the system for normal operation. If the condition persists, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to B6.
- B6 REPOWER THE FIRE SUPPRESSION SYSTEM
- Verify that the fire suppression system is repowered. Refer to FIRE SUPPRESSION SYSTEM article.
- Is the fire suppression system repowered?
WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article. Failure to follow these instructions may result in serious personal injury.- YES : Fire suppression system repowering is complete.
- NO : REFER to FIRE SUPPRESSION SYSTEM article for fire suppression system depowering and repowering procedure.
PINPOINT TEST C: THE CONTROL LINKAGE IS BINDING
- C1 CHECK THE SHIFT CONTROL COMPONENTS FOR DAMAGE
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Gain access to the shift control components.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe all shift control components while attempting to shift the selector lever through all ranges.
- Are any of the components damaged?
WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in FIRE SUPPRESSION SYSTEM article. Failure to follow the instructions may result in serious personal injury. - C2 CHECK THE SHIFT CONTROL COMPONENT OPERATION WITH THE SELECTOR LEVER CABLE DISCONNECTED FROM THE TRANSMISSION
- Key in OFF position.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Disconnect the selector lever cable from the manual control lever.
- Lower the vehicle.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe the shift control components while attempting to shift the selector lever through all ranges.
- Do the components move fluidly through all ranges?
- YES : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to C4.
- NO : Go to C3.
- C3 CHECK THE SHIFT CONTROL COMPONENT OPERATION WITH THE SELECTOR LEVER CABLE DISCONNECTED FROM THE STEERING COLUMN
- Key in OFF position.
- Disconnect the selector lever cable from the transmission selector lever arm and support.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe the shift control components while attempting to shift the selector lever through all ranges.
- Do the components move fluidly through all ranges?
- YES : INSTALL a new selector lever cable and bracket. REFER to Selector Lever Cable and Bracket - Column Shift . TEST the system for normal operation. If equipped with fire suppression system, go to C4.
- NO : REFER to STEERING COLUMN article for steering column repair. If equipped with fire suppression system, go to C4.
- C4 REPOWER THE FIRE SUPPRESSION SYSTEM
- Verify that the fire suppression system is repowered. Refer to FIRE SUPPRESSION SYSTEM article.
- Is the fire suppression system repowered?
WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article. Failure to follow these instructions may result in serious personal injury.- YES : Fire suppression system repowering is complete.
- NO : REFER to FIRE SUPPRESSION SYSTEM article for fire suppression system depowering and repowering procedure.
PINPOINT TEST D: THE TRANSMISSION CONTROL (TC) SWITCH DOES NOT OPERATE CORRECTLY - COLUMN SHIFT
- D1 CHECK FUSE 26 (10A)
- Check fuse: Central Junction Box (CJB) 26 (10A)
- Is the resistance less than 5 ohms?
- D2 CHECK CIRCUIT 640 (RD/YE) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: CJB Fuse 26 (10A)
- Disconnect: PCM C175b
- Disconnect: Instrument Panel Cluster C2220
- Disconnect: Transmission Control (TC) Switch C279
- Measure the resistance between the output side of CJB F26 (10A) and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to D4.
- NO : REPAIR circuit 640 (RD/YE). REINSTALL all components. TEST the system for normal operation.
- D3 CHECK CIRCUIT 640 (RD/YE) FOR AN OPEN
- Key in OFF position.
- Disconnect: CJB Fuse 26 (10A)
- Disconnect: Transmission Control (TC) Switch C279
- Measure the resistance between the output side of CJB fuse 26 (10A) and TC switch C279-1, circuit 640 (RD/YE), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to D5.
- NO : REPAIR circuit 640 (RD/YE). RECONNECT all components. TEST the system for normal operation.
- D4 CHECK THE SELECTOR LEVER HARNESS FOR A SHORT TO GROUND
- Measure the resistance between TC switch C279-1, component side, and ground while cycling the TC switch.
- Is the resistance greater than 10,000 ohms?
- YES : Go to D6.
- NO : INSTALL a new selector lever. REFER to Selector Lever - Column Shift . RECONNECT all components. TEST the system for normal operation.
- D5 CHECK THE TC SWITCH
- Measure the resistance between TC switch C279-1 and C279-2, component side, while cycling the TC switch.
- Does the resistance change from less than 5 ohms to greater than 10,000 ohms?
- YES : Go to D7.
- NO : INSTALL a new selector lever. REFER to Selector Lever - Column Shift . REINSTALL all components. TEST the system for normal operation.
- D6 CHECK CIRCUIT 224 (TN/WH) FOR A SHORT TO GROUND
- Measure the resistance between TC switch C279-2, circuit 224 (TN/WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : INSTALL a new PCM. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 224 (TN/WH). RECONNECT all components. TEST the system for normal operation.
- D7 CHECK CIRCUIT 224 (TN/WH) FOR AN OPEN
- Disconnect: PCM C175b
- Measure the resistance between TC switch C279-2, circuit 224 (TN/WH), harness side and PCM C175b-27, circuit 224 (TN/WH), harness side.
- Is the resistance less than 5 ohms?
- YES : INSTALL a new PCM. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 224 (TN/WH). RECONNECT all components. TEST the system for normal operation.
PINPOINT TEST E: THE BRAKE SHIFT INTERLOCK SYSTEM DOES NOT RELEASE/LOCK CORRECTLY - FLOOR SHIFT
- E1 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Disconnect: Brake Shift Interlock Actuator (BSIA) C2322
- Measure the resistance from BSIA C2322-2, circuit 57 (BK), harness side to ground.
- Is the resistance less than 5 ohms?
- YES : Go to E2.
- NO : REPAIR circuit 57 (BK). RECONNECT all components. TEST the system for normal operation.
- E2 CHECK CIRCUIT 1040 (RD/BK) FOR VOLTAGE
- Key in ACCESSORY position.
- Measure the voltage at BSIA C2322-1, circuit 1040 (RD/BK), harness side.
- Is the voltage greater than 10 volts?
- E3 CHECK CIRCUIT 1651 (WH/RD) FOR VOLTAGE
- Measure the voltage at BSIA C2322-3, circuit 1651 (WH/RD), harness side, while pressing and releasing the brake pedal.
- Is the voltage greater than 10 volts with the brake pedal pressed, and less than 5 volts with it released?
- YES : INSTALL a new BSIA. REFER to Brake Shift Interlock Actuator - Floor Shift .
- NO : For voltage less than 5 volts, Go to E8.
- For voltage more than 10 volts, Go to E21.
- E4 CHECK THE CENTRAL JUNCTION BOX (CJB) FUSE 17 (10A) INPUT VOLTAGE
- Measure the voltage at the input side of CJB fuse 17 (10A).
- Is the voltage greater than 10 volts?
- YES : Go to E5.
- NO : INSTALL a new CJB. RECONNECT all components. TEST the system for normal operation.
- E5 CHECK CJB FUSE 17 (10A)
- Check fuse: CJB 17 (10A)
- Is the resistance less than 5 ohms?
- E6 CHECK CIRCUIT 1040 (RD/BK) FOR AN OPEN
- Remove CJB fuse 17 (10A).
- Measure the resistance from the output side of the CJB fuse 17 (10A), to the BSIA C2322-1, circuit 1040 (RD/BK), harness side.
- Is the resistance less than 5 ohms?
- YES : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- NO : Repair circuit 1040 (RD/BK). RECONNECT all components. TEST the system for normal operation.
- E7 CHECK CIRCUIT 1040 (RD/BK) FOR A SHORT TO GROUND
- Remove CJB fuse 17 (10A).
- Measure the resistance between the BSIA C2322-1, circuit 1040 (RD/BK), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : INSTALL a new BSIA. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 1040 (RD/BK). RECONNECT all components. TEST the system for normal operation.
- E8 CHECK BATTERY JUNCTION BOX (BJB) FUSE 14 (20A) INPUT VOLTAGE
- Measure the voltage at the input side of BJB fuse 14 (20A).
- Is the voltage greater than 10 volts?
- YES : Go to E9.
- NO : INSTALL a new BJB. RECONNECT all components. TEST the system for normal operation.
- E9 CHECK BJB FUSE 14 (20A)
- Check fuse: BJB 14 (20A)
- Is the resistance less than 5 ohms?
- E10 CHECK CJB FUSE 28 (7.5A)
- Check fuse: CJB 28 (7.5A)
- Is the resistance less than 5 ohms?
- E11 CHECK CIRCUIT 1119 (RD) FOR AN OPEN
- Disconnect: Brake Pedal Position (BPP) Switch C278
- Measure the resistance between the output side of BJB fuse 14 (20A), and BPP switch C278-3, circuit 1119 (RD), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to E12.
- NO : REPAIR circuit 1119 (RD). RECONNECT all components. TEST the system for normal operation.
- E12 CHECK THE BPP SWITCH
- Measure the resistance between the BPP switch pin 3 and pin 4, component side, while pressing and releasing the brake pedal.
- Is the resistance less than 5 ohms with the brake pedal depressed, and greater than 10,000 ohms with it released?
- YES : Go to E13.
- NO : INSTALL a new BPP switch. RECONNECT all components. TEST the system for normal operation.
- E13 CHECK CIRCUIT 511 (LG) FOR AN OPEN
- Remove CJB fuse 28 (7.5A)
- Measure the resistance between the BPP switch C278-4, harness side, and the input side of CJB fuse 28 (7.5A).
- Is the resistance less than 5 ohms?
- YES : Go to E14.
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- E14 CHECK CIRCUIT 1651 (WH/RD) FOR AN OPEN
- Measure the resistance between the output side of CJB fuse 28 (7.5A), and the BSIA C2322-3, circuit 1651 (WH/RD), harness side.
- Is the resistance less than 5 ohms?
- YES : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
- E15 CHECK CIRCUIT 1119 (RD) FOR A SHORT TO GROUND
- Disconnect: BPP Switch C278
- Remove BJB fuse 14 (20A).
- Measure the resistance between the BPP C278-3, circuit 1119 (RD), harness side and ground, while pressing and releasing the brake pedal.
- Is the resistance always greater than 10,000 ohms?
- E16 CHECK THE BPP
- Measure the resistance between the BPP pins 1 and 4 and pins 2, 3 and 5, component side, while pressing and releasing the brake pedal.
- Are the resistances less than 5 ohms with the brake pedal pressed, and greater than 10,000 ohms with it released?
- YES : Go to E17.
- NO : REPLACE the BPP. RECONNECT all components. TEST the system for normal operation.
- E17 CHECK CIRCUIT 511 (LG)
- Remove the CJB fuse 28 (7.5A).
- Measure the resistance between the BPP C278-4, circuit 511 (LG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to E18
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- E18 CHECK CIRCUIT 1651 (WH/RD) FOR A SHORT TO GROUND
- Disconnect: Lighting Control Module (LCM) C2145b
- Disconnect: ABS Control Module C135
- Remove the CJB fuse 28 (7.5A).
- Measure the resistance between the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to E19.
- NO : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
- E19 CHECK ABS MODULE FOR AN INTERNAL SHORT
- Connect: ABS Control Module C135
- Measure the resistance between the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to E20.
- NO : INSTALL a new ABS module. RECONNECT all components. TEST the system for normal operation.
- E20 CHECK LCM MODULE FOR AN INTERNAL SHORT
- Disconnect: ABS Control Module C135
- Connect: LCM C2145b
- Measure the resistance between the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : INSTALL a new BSIA. RECONNECT all components. TEST the system for normal operation.
- NO : INSTALL a new LCM module. RECONNECT all components. TEST the system for normal operation.
- E21 CHECK BSIA VOLTAGE CIRCUITS FOR A SHORT TO POWER
- Remove BJB fuse 14 (20A).
- Measure the voltage at the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- E22 CHECK BPP SWITCH FOR INTERNAL SHORT
- Measure the resistance between the BPP switch pin 3 and pin 4, component side, with the brake pedal released.
- Is the resistance less than 10,000 ohms?
- YES : INSTALL a new BPP switch. RECONNECT all components. TEST the system for normal operation.
- NO : Problem may be intermittent. RECONNECT all components. TEST the system for normal operation.
- E23 CHECK BSIA VOLTAGE CIRCUITS FOR A SHORT TO POWER
- Remove CJB fuse 28 (7.5A).
- Measure the voltage at the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : Go to E24.
- NO : REPAIR circuit 511 (LG). RECONNECT all components. TEST the system for normal operation.
- E24 CHECK ABS MODULE FOR A SHORT TO POWER
- Disconnect: ABS Control Module C135
- Measure the voltage at the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : Go to E25.
- NO : INSTALL a new ABS module. RECONNECT all components. TEST the system for normal operation.
- E25 CHECK LCM FOR A SHORT TO POWER
- Disconnect: LCM C2145b
- Measure the voltage at the BSIA C2322-3, circuit 1651 (WH/RD), harness side and ground.
- Is the voltage greater than 10 volts?
- YES : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
- NO : INSTALL a new LCM. RECONNECT all components. TEST the system for normal operation.
- E26 CHECK THE DEACTIVATOR SWITCH
- Disconnect: Deactivator Switch C272
- Measure the resistance between the deactivator switch pin 1 and pin 2, component side, while pressing and releasing the brake pedal.
- Is the resistance less than 5 ohms with the brake pedal depressed, and greater than 10,000 ohms with it released?
- YES : Go to E27.
- NO : INSTALL a new deactivator switch. REINSTALL all components. TEST the system for normal operation.
- E27 CHECK CIRCUIT 636 (OG)
- Disconnect: PCM C175b
- Measure the resistance between the deactivator switch C277-2, circuit 636 (OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : CONNECT PCM C175b, deactivator switch C277 and INSTALL BJB F14 (20A), then press the brake pedal. If BJB F14 (20A) fails, INSTALL a new PCM.
- NO : REPAIR circuit 636 (RD). REINSTALL all components. TEST the system for normal operation.
PINPOINT TEST F: THE SELECTOR LEVER IS OUT OF CORRECT GEAR RELATIONSHIP - FLOOR SHIFT
- F1 CHECK THE SHIFT CONTROL COMPONENTS FOR DAMAGE
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Gain access to the shift control components.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe all shift control components while shifting the selector lever through all ranges.
- Are any of the components damaged?
WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in FIRE SUPPRESSION SYSTEM article. Failure to follow the instructions may result in serious personal injury. - F2 CHECK THE SELECTOR LEVER CABLE AND BRACKET INSTALLATION
- Check to make sure the selector lever cable and bracket installation is correct. Refer to Selector Lever Cable and Bracket - Floor Shift .
- Is the selector lever cable and bracket installed correctly?
- F3 CHECK THE SELECTOR LEVER CABLE ADJUSTMENT
- Check to make sure the selector lever cable adjustment is correct. Refer to Selector Lever Cable Adjustment - Floor Shift .
- Is the selector lever cable adjusted correctly?
- F4 CHECK THE TRANSMISSION RANGE (TR) SENSOR ADJUSTMENT
- Check to make sure the TR sensor adjustment is correct. Refer to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article.
- Is the TR sensor adjusted correctly?
- YES : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to F5.
- NO : ADJUST the TR sensor. TEST the system for normal operation. If the condition persists, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to F5.
- F5 REPOWER THE FIRE SUPPRESSION SYSTEM
- Verify that the fire suppression system is repowered. Refer to FIRE SUPPRESSION SYSTEM article.
- Is the fire suppression system repowered?
WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article. Failure to follow these instructions may result in serious personal injury.- YES : Fire suppression system repowering is complete.
- NO : REFER to FIRE SUPPRESSION SYSTEM article for fire suppression system depowering and repowering procedure.
PINPOINT TEST G: THE SELECTOR LEVER LINKAGE IS BINDING - FLOOR SHIFT
- G1 CHECK THE SHIFT CONTROL COMPONENTS FOR DAMAGE
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Gain access to the shift control components.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe all shift control components while attempting to shift the selector lever through all ranges.
- Are any of the components damaged?
WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in FIRE SUPPRESSION SYSTEM article. Failure to follow the instructions may result in serious personal injury. - G2 CHECK THE SHIFT CONTROL COMPONENT OPERATION WITH THE SELECTOR LEVER CABLE DISCONNECTED FROM THE TRANSMISSION
- Key in OFF position.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING article.
- Disconnect the selector lever cable from the manual control lever.
- Lower the vehicle.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe the shift control components while attempting to shift the selector lever through all ranges.
- Do the components move fluidly through all ranges?
- YES : REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70E/4R75E article for internal transmission repair. If equipped with fire suppression system, go to G4.
- NO : Go to G3.
- G3 CHECK THE SHIFT CONTROL COMPONENT OPERATION WITH THE SELECTOR LEVER CABLE DISCONNECTED FROM THE FLOOR SHIFT MECHANISM
- Key in OFF position.
- Disconnect the selector lever cable from the floor shift mechanism.
- Key in ACCESSORY position.
- Apply the brake pedal.
- Observe the shift control components while attempting to shift the selector lever through all ranges.
- Do the components move fluidly through all ranges?
- YES : INSTALL a new selector lever cable and bracket. REFER to Selector Lever Cable and Bracket - Floor Shift . TEST the system for normal operation. If equipped with fire suppression system, go to G4.
- NO : INSTALL a new floor shift mechanism. REFER to Selector Lever - Floor Shift . If equipped with fire suppression system, go to G4.
- G4 REPOWER THE FIRE SUPPRESSION SYSTEM
- Verify that the fire suppression system is repowered. Refer to FIRE SUPPRESSION SYSTEM article.
- Is the fire suppression system repowered?
WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to FIRE SUPPRESSION SYSTEM article. Failure to follow these instructions may result in serious personal injury.- YES : Fire suppression system repowering is complete.
- NO : REFER to FIRE SUPPRESSION SYSTEM article for fire suppression system depowering and repowering procedure.
PINPOINT TEST H: THE TRANSMISSION CONTROL (TC) SWITCH DOES NOT OPERATE CORRECTLY - FLOOR SHIFT
- H1 CHECK CENTRAL JUNCTION BOX (CJB) FUSE 26 (10A)
- Check fuse: CJB 26 (10A)
- Is the resistance less than 5 ohms?
- H2 CHECK CIRCUIT 640 (RD/YE) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: CJB Fuse 26 (10A)
- Disconnect: Instrument Cluster (IC) C2220
- Measure the resistance between the output side of fuse 26 (10A) and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to H4.
- NO : REPAIR circuit 640 (RD/YE). REINSTALL all components. TEST the system for normal operation.
- H3 CHECK CIRCUIT 640 (RD/YE) FOR AN OPEN
- Key in OFF position.
- Disconnect: CJB Fuse 26 (10A)
- Disconnect: Selector Lever C3247
- Measure the resistance between the output side of fuse 26 (10A) and selector lever C3247-3, circuit 640 (RD/YE), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to H5.
- NO : REPAIR circuit 640 (RD/YE). RECONNECT all components. TEST the system for normal operation.
- H4 CHECK THE SELECTOR LEVER HARNESS FOR SHORT TO GROUND
- Key in OFF position.
- Disconnect: Selector Lever C3247
- Measure the resistance between selector lever C3247-3, component side, and ground while cycling the transmission control (TC) switch.
- Is the resistance greater than 10,000 ohms?
- YES : Go to H6.
- NO : INSTALL a new selector lever. REFER to Selector Lever - Floor Shift . RECONNECT all components. TEST the system for normal operation.
- H5 CHECK THE TC SWITCH
- Key in OFF position.
- Measure the resistance between selector lever C3247-3 and C3247-1, component side, while cycling the TC switch.
- Does the resistance change from less than 5 ohms to greater than 10,000 ohms?
- YES : Go to H7.
- NO : INSTALL a new TC switch. REFER to Selector Lever - Floor Shift . REINSTALL all components. TEST the system for normal operation.
- H6 CHECK CIRCUIT 224 (TN/WH) FOR A SHORT TO GROUND
- Disconnect: PCM C175b
- Measure the resistance between selector lever C3247-1, circuit 224 (TN/WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : INSTALL a new PCM. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 224 (TN/WH). RECONNECT all components. TEST the system for normal operation.
- H7 CHECK CIRCUIT 224 (TN/WH) FOR AN OPEN
- Disconnect: PCM C175b
- Measure the resistance between selector lever C3247-1, circuit 224 (TN/WH), harness side, and PCM C175b-29, circuit 224 (TN/WH), harness side.
- Is the resistance less than 5 ohms?
- YES : INSTALL a new PCM. RECONNECT all components. TEST the system for normal operation.
- NO : REPAIR circuit 224 (TN/WH). RECONNECT all components. TEST the system for normal operation.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.