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 THE COOLANT LEVEL AND CONDITION
WARNING:
Never open the cooling system when the engine is hot. The system is under pressure. Extreme burns or scalding may result. Failure to follow these instructions can result in possible serious or fatal injury. Allow the engine to cool before opening the cooling system.
1. Inspect the cooling system for proper level and condition.
  Is the coolant level and condition OK?
  
  Yes
  - Go To 2
  No
  - Inspect the vehicle for a coolant leak, make the appropriate repairs and add the correct amount of coolant. Refer to SPECIFICATIONS .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
CHECK FOR AN ACTIVE DTC
NOTE:
Diagnose and repair DTC P060B before proceeding with this test.

NOTE:
Extremely cold ambient temperatures may cause this DTC to set.
1. Start the engine and allow it to reach operating temperature.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 3
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to .
CHECK FOR HIGH RESISTANCE IN THE (K2) ECT SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the ECT Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
  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.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Measure the resistance of the (K2) ECT Signal circuit between the ECT Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K2) ECT Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
CHECK FOR HIGH RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
1. Measure the resistance of the (K900) Sensor Ground circuit between the ECT Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K900) Sensor Ground for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
ENGINE COOLANT TEMPERATURE SENSOR
1. Turn the ignition off.
2. Reconnect the PCM C2 harness connector.
3. Replace the Engine Coolant Temperature Sensor in accordance with the Service Information. Refer to SENSOR, COOLANT TEMPERATURE , REMOVAL .
4. Start the engine and allow it to idle for up to two minutes.
5. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 6
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
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 MODULE, POWERTRAIN CONTROL, 2.8L DIESEL [ENS] , REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to .
  - Test complete.