Diagnostic Test

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, erase DTCs in the PCM.
3. Press and release the clutch pedal several times.
4. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT DTC diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (T141) CLUTCH INTERLOCK SWITCH SIGNAL CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the Clutch Interlock Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (T141) Clutch Interlock Switch Signal circuit in the Clutch Interlock Switch harness connector.
  Is the voltage above 10.0 volts?
  
  Yes
  - Go To 3
  No
  - Go To 5
CHECK THE (Z905) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Using a 12-volt test light connected to 12 volts, probe the (Z905) Ground circuit at the Clutch Interlock Switch harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 4
  No
  - Repair the (Z905) Ground for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE CLUTCH INTERLOCK SWITCH
1. Turn the ignition off.
2. Connect a jumper between the (Z905) Ground circuit and the (T141) Clutch Interlock Switch Signal circuit at the Clutch Interlock Switch harness connector.
3. Turn the ignition on.
4. With the scan tool, monitor the Clutch Interlock status.
  NOTE:
  The scan tool should display the Clutch Interlock status as pressed with the jumper in place and not pressed with the jumper removed.
  
  Does the scan tool display the status as described above?
  
  Yes
  - Replace the Clutch Interlock Switch in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (T141) CLUTCH INTERLOCK SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (T141) Clutch Interlock Switch Signal circuit at the Clutch Interlock Switch harness connector.
  Is there continuity between ground and the (T141) Clutch Interlock Switch Signal circuit?
  
  Yes
  - Repair the (T141) Clutch Interlock Switch Signal circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK THE (T26) CLUTCH UPSTOP SWITCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Clutch Switch harness connector.
3. Check for continuity between ground and the (T26) Clutch Upstop Switch Signal circuit at the Clutch Switch harness connector.
  Is there continuity between ground and the (T26) Clutch Upstop Switch Signal circuit?
  
  Yes
  - Repair the (T26) Clutch Upstop Switch Signal circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
CHECK THE (T141) CLUTCH INTERLOCK SWITCH SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the (T141) Clutch Interlock Switch Signal circuit between the Clutch Interlock Switch harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (T141) Clutch Interlock Switch Signal circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (T26) CLUTCH UPSTOP SWITCH SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (T26) Clutch Upstop Switch Signal circuit between the Clutch Switch harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Repair the (T26) Clutch Upstop Switch Signal circuit for an open or high resistance.
  - Perform the PCM 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 [EHD, ERB], REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.