Diagnostic Test
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR DTC TO RETURN NOTE:
Before proceeding with the diagnostic procedure, verify that the connections are properly made, seated and verify proper pin terminal tension. A loose connection at any of the SCM connectors may cause the DTC to set.
- With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
- For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Go To 2
No
- Test complete. The condition or conditions that originally set this DTC are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAMS as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
- CHECK THE (V71) S/C SIGNAL 2 CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the harness connector at the component of the circuit being tested. Note: Use the appropriate SYSTEM WIRING DIAGRAM as a guide to follow the path of the circuit.
- Turn the ignition on.
- Using a DVOM, measure the voltage of the circuit being tested at the component harness connector.
NOTE:The voltage on a 5.0 volt signal or reference circuit should be between approximately 4.8 and 5.2 volts.
Is the voltage above 5.2 volts?
Yes
- Go To 3
No
- Go To 4
- ISOLATE AND CHECK THE (V71) S/C SIGNAL 2 CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE SCCM HARNESS CONNECTOR
- The ignition must be off when performing a resistance check to find a short between circuits.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) 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.
- Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
- With the other lead of the DVOM probe all other circuits at the ECU harness connector.
NOTE:When probing a circuit at an Electronic Control Unit (ECU) harness connector, always use an appropriate back probing tool to prevent any possible damage to the ECU terminals.
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 4
- ISOLATE AND CHECK THE (V937) SENSOR/SWITCH GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the 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.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the ECU harness connector and measure the resistance of the circuit.
NOTE:When probing a circuit at an Electronic Control Unit (ECU) harness connector, always use an appropriate back probing tool to prevent any possible damage to the ECU terminals.
Is the resistance below 3.0 Ohms?
Yes
- Replace the Right Steering Wheel Switch (Speed Control Switch) in accordance with the Service Information. Refer to SWITCH, SPEED CONTROL, REMOVAL AND INSTALLATION .
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Repair the circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .