Diagnostic Test
WARNING: This page is about a different variant/trim than selected.
- CHECK FOR AN ACTIVE DTC
- Turn the ignition on.
- With the scan tool, read DTCs and record on the repair order.NOTE:
It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
Is the DTC active or pending?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- BRAKE SWITCH
- Turn the ignition off.
- Disconnect the Brake Switch harness connector.
- Measure the resistance between terminal 1 and terminal 4 at the Brake Switch.
- Measure the resistance between terminal 2 and terminal 3 at the Brake Switch.
- Apply and release the Brake Switch plunger while monitoring the Ohmmeter.
Does the resistance change from below 3.0 Ohms to an open circuit for one or both of the measurements taken?
Yes
- Go To 3
No
- Verify that there is good pin to terminal contact in the Switch and Powertrain Control Module harness connectors. If no problems are found, replace the Brake Lamp Switch. Refer to SWITCH, STOP LAMP .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (L56) BRAKE LAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the PCM C1 harness connector.
- Turn the ignition on.
- Measure the voltage on the (L56) Brake Lamp Switch Output circuit at the Brake Switch harness connector.
Is the any voltage present?
Yes
- Repair the (L56) Brake Lamp Switch Output circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- CHECK RELATED PCM AND COMPONENT CONNECTIONS
- Perform any Service Bulletins that apply.
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
- Proper connector installation.
- Damaged connector locks.
- Corrosion.
- Other signs of water intrusion.
- Weather seal damage (if equipped).
- Bent terminals.
- Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
- Terminals that have been pushed back into the connector cavity.
- Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
- Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace the Powertrain Control Module in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Test complete.