Diagnostic Test

With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.

1. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
2. With the scan tool, erase all DTCs.
3. Turn the ignition off for a minimum of 10.0 seconds.
4. Turn the ignition on.
5. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
6. With the scan tool, read DTCs.

Did the DTC return?

Yes 

• Go To  2

No 

• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

Does the (F917) Fused Ignition Circuit have an open 20A fuse?

Yes 

• Repair the Open Fuse.
• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

No 

• Go To  3

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Comfort Seat Rear Module (CRSM) and every component harness connector containing the circuit being tested. Note:  Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
   NOTE:

   There should be no continuity between ground and the circuit being tested.

Is there continuity between ground and the circuit being tested?

Yes 

• Repair the circuit for a short to ground. Use the appropriate SYSTEM WIRING DIAGRAM as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

No 

• Go To  4

1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the Comfort Rear Seat Module (CRSM) and every component harness connector containing the circuit being tested. At this time leave all in-line connectors connected. Note:  Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
3. Connect one lead of the DVOM to the circuit being tested at the CRSM harness connector.
4. With the other lead of the DVOM probe all other circuits at the CRSM harness connector.
   NOTE:

   With the circuit isolated there should be no continuity between the circuit being tested and any other circuit.

Is there continuity between the circuit being tested and any other circuit?

Yes 

• Repair the short between the circuits that have continuity. Use the appropriate SYSTEM WIRING DIAGRAM as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

No 

• Go To  5

1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Comfort Rear Seat Module (CRSM) and every component harness connector containing the circuit being tested. Note:  Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
   NOTE:

   There should be no continuity between ground and the circuit being tested.

Is there continuity between ground and the circuit being tested?

Yes 

• Repair the circuit for a short to ground. Use the appropriate SYSTEM WIRING DIAGRAM as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

No 

• Go To  6

1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the Comfort Seat Rear Module (CRSM) and every component harness connector containing the circuit being tested. At this time leave all in-line connectors connected. Note:  Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
3. Connect one lead of the DVOM to the circuit being tested at the CRSM harness connector.
4. With the other lead of the DVOM probe all other circuits at the CRSM harness connector.
   NOTE:

   With the circuit isolated there should be no continuity between the circuit being tested and any other circuit.

Is there continuity between the circuit being tested and any other circuit?

Yes 

• Repair the short between the circuits that have continuity. Use the appropriate SYSTEM WIRING DIAGRAM as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
• Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

No 

• Go To  7

1. The ignition must be off when performing a load test on a circuit.
2. Isolate the circuit by disconnecting the Comfort Seat Rear Module (CRSM) and every component harness connector containing the circuit being tested.
3. Connect the positive lead of the load test tool to the positive side of the Battery (A). Note:  . Refer to the diagram below.
4. Using an approved back probe tool, connect the negative lead of the load test tool to the circuit being tested at the one of the component harness connectors (B).
5. Using an approved back probe tool and a fused jumper wire, connect the circuit being tested to the negative side of the Battery or a known good ground at the other component harness connector (C and D).
6. The bulb on the load test tool should be illuminated and bright if there is no resistance in the circuit.
   NOTE:

   Note: Why load test a circuit?  A load test is used to determine if a circuit is capable of carrying the amperage needed to perform properly. The 3156 bulb in the load tool illustrated, is a simple but effective method of testing circuit functionality. A 3156 Bulb has approximately 6.0 Ohms of resistance when the bulb is powered  and draws approximately 2.0 amps of current. Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool and for additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .