Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 2500 HD and 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

HIGH RESISTANCE IN THE CNG RAIL PRESSURE SENSOR CIRCUITS
NOTE:
Extremely high ambient temperatures could cause this DTC to set.
1. Turn the ignition off.
2. Disconnect the Fuel Rail 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:
  - (K162) CNG Rail Pressure Sensor circuit between the Fuel Rail Sensor harness connector and the GPEC Adaptor.
  - (K900) Sensor Return circuit between the Fuel Rail Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms for both circuits?
  
  Yes
  - Go To 2
  No
  - Repair the circuit that measured above 5.0 Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CNG RAIL SENSOR
1. Replace the CNG Rail Sensor in accordance with the service information.
2. Reconnect the PCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Start the engine and test drive the vehicle in CNG fuel mode.
6. With the scan tool, view DTCs
  Did the DTC return?
  
  Yes
  - Go To 3
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CNG PRESSURE REGULATOR
1. Replace the CNG Pressure Regulator in accordance with the service information.
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. Start the engine and test drive the vehicle in CNG fuel mode.
5. With the scan tool, view DTCs
  Did the DTC return?
  
  Yes
  - Go To 4
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the CNG Rail Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .