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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 958 (CRUISE CONTROL SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESCRUISE CONTROL INOPERATIVE/MALFUNCTIONING (6.6L)CONDITIONS FOR ENABLING CRUISE CONTROL
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Conditions for Enabling Cruise Control

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Conditions for Enabling Cruise Control
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  • The vehicle speed is greater than 40 km/h (25 mph).
  • The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
  • The system voltage is between 12 volts and 16 volts.
Cruise Control Inoperative/Malfunctioning (6.6L)

Step Action Yes No
Schematic Reference: Cruise Control Schematics 
Connector End View Reference: Cruise Control Connector End Views  or Engine Control Module (ECM) Connector End Views in Engine Controls - 6.6L (LB7) or to Engine Control Module (ECM) Connector End Views in Engine Controls - 6.6L (LLY)
1 Did you perform the Cruise Control Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Cruise Control 
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Turn the cruise control On/Off switch OFF.
  4. With the scan tool, observe the Cruise On/Off Switch parameter in the PCM Engine Data 1 data list.
Does the Cruise On/Off Switch parameter display Off?		 Go to Step 3  Go to Step 6 
3
  1. Turn the cruise control On/Off switch ON.
  2. With the scan tool, observe the Cruise On/Off Switch parameter.
Does the Cruise On/Off Switch parameter display On?		 Go to Step 4  Go to Step 10 
4
  1. With the scan tool, observe the Cruise Set/Coast Switch parameter in the PCM Engine Data 1 data list.
  2. Turn the cruise control On/Off switch ON.
  3. Press and hold the cruise control Set/Coast switch.
Does the Cruise Set/Coast Switch parameter display On?		 Go to Step 5  Go to Step 7 
5
  1. With the scan tool, observe the Cruise Resume/Accel. Switch parameter in the PCM data list.
  2. Press and hold the Resume/Accel switch.
Does the Cruise Resume/Accel. Switch parameter display On?		 Go to Step 9  Go to Step 8 
6
  1. Turn OFF the ignition.
  2. Disconnect the cruise control switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the cruise control on switch signal circuit and a good ground.
Does the test lamp illuminate?		 Go to Step 11  Go to Step 20 
7
  1. Turn OFF the ignition.
  2. Disconnect the cruise control switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a 3 ampere fused jumper between the cruise control set/coast switch signal circuit and the ignition 3 voltage circuit.
  5. With the scan tool, observe the Cruise Set/Coast Switch parameter.
Does the Cruise Set/Coast Switch parameter display On?		 Go to Step 20  Go to Step 15 
8
  1. Turn OFF the ignition.
  2. Disconnect the cruise control switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a 3 ampere fused jumper between the cruise control resume/accel switch signal circuit and the ignition 3 voltage circuit.
  5. With the scan tool, observe the Cruise Resume/Accel. Switch parameter.
Does the Cruise Resume/Accel. Switch parameter display On?		 Go to Step 20  Go to Step 16 
9
  1. With the scan tool, observe the TCC Cruise Brake Pedal parameter in the PCM Engine Data 1 data list.
  2. Depress the brake pedal.
Does the TCC Cruise Brake Pedal parameter display Applied?		 Go to Diagnostic Aids Go to Step 17 
10
  1. Turn OFF the ignition.
  2. Disconnect the cruise control switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 3 voltage circuit and a good ground.
Does the test lamp illuminate?		 Go to Step 12  Go to Step 18 
11 Test the cruise control on switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 21 
12 Test the cruise control on switch signal circuit for an open, for a high resistance or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 13 
13 Test the cruise control resume/accel switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 14 
14 Test the cruise control set/coast switch signal circuit for a for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 20 
15 Test the cruise control set/coast switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 21 
16 Test the cruise control resume/accel switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 21 
17 Test the TCC/Brake switch signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 19 
18 Repair the open, the high resistance, or the short to ground in the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 25  -
19 Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 22 
20 Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 23 
21 Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 25  Go to Step 24 
22 Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Lighting Systems.
Did you complete the replacement?		 Go to Step 25  -
23 Replace the multifunction turn signal lever. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column.
Did you complete the replacement?		 Go to Step 25  -
24
IMPORTANT: Program the replacement ECM.
Replace the ECM. Refer to Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LB7) or to Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LLY).Did you complete the replacement?		 Go to Step 25  -
25 Operate the vehicle within the conditions for cruise control operation.
Does the cruise control system operate properly?		 System OK Go to Step 2 
RENDER: 1.0x

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