Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN ACTIVE DTC
NOTE:
Make sure the Stop Lamp Switch is properly adjusted before continuing.
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
3. Press and release the Brake Pedal.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (L56) BRAKE LAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Stop Lamp Switch harness connector.
3. Disconnect the PCM C1 harness connector.
4. Check for continuity between ground and the (L56) Brake Lamp Switch Output circuit at the Stop Lamp Switch harness connector.
  Is there continuity between ground and the (L56) Brake Lamp Switch Output circuit?
  
  Yes
  - Repair the (L56) Brake Lamp Switch Output circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (L56) BRAKE LAMP SWITCH OUTPUT CIRCUIT FOR AN OPEN
1. Disconnect the PCM C1 harness connector.
2. Measure the resistance of the (L56) Brake Lamp Switch Output circuit between the Stop Lamp Switch harness connector and the appropriate terminal of the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (L56) Brake Lamp Switch Output circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
STOP LAMP SWITCH
1. Measure the resistance between terminal 1 and terminal 2 at the Stop Lamp Switch.
2. Next, measure the resistance between terminal 3 and terminal 4 at the Stop Lamp Switch.
3. Apply and release the Stop Lamp Switch while monitoring the Ohmmeter.
  Does the resistance change from below 5.0 Ohms to an open circuit for one or both of the measurements taken?
  
  Yes
  - Go To 5
  No
  - Verify that there is good pin to terminal contact in the Switch and Powertrain Control Module harness connectors. If OK, replace the Stop Lamp Switch. Refer to SWITCH, STOP LAMP .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. 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.