2014 Jeep Wrangler JK Factory Service Manual 29 - Non-DTC Diagnostics

NO RESPONSE FROM PCM (POWERTRAIN CONTROL MODULE) - GAS

Special Tools: Click to display a list of tools used in this procedure

For a complete wiring diagram, refer to the Wiring Information.






Possible Causes

FUSED B(+) CIRCUIT OPEN OR SHORTED
GROUND CIRCUIT OPEN
FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR SHORTED
FUSED ASD/MAIN RELAY OUTPUT CIRCUIT OPEN OR SHORTED
CAN C BUS (+) CIRCUIT OPEN
CAN C BUS (-) CIRCUIT OPEN
POWERTRAIN CONTROL MODULE (PCM)

1. TEST FOR INTERMITTENT CONDITION




NOTE: Check for any TSB(s) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.
1. Turn the ignition on.

NOTE: Make sure the Ignition Off Draw (IOD) fuse is installed and battery voltage is between 10.0 and 16.0 volts.
2. With the scan tool, read the module status.

NOTE: Check the TIPM for any active CAN hardware DTCs, perform DTC before proceeding.


Does the scan tool indicate that the module is active on the bus?

Yes


No


2. CHECK THE (A209) FUSED B(+) CIRCUIT FOR AN OPEN OR SHORT


1. Turn the ignition off.
2. Disconnect the PCM C1 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.

3. Connect the Adapter, GPEC Diagnostic 10436 .
4. Using a 12-volt test light connected to ground, probe the (A209) Fused B(+) circuit at the GPEC Adaptor.


Does the test light illuminate brightly?

Yes


No


3. CHECK THE (Z921) GROUND CIRCUITS FOR AN OPEN


1. Turn the ignition off.
2. Using a 12 volt test light connected to 12 volts, probe each of the (Z921) Ground circuits at the GPEC Adaptor.
3. Wiggle test each circuit during the test to check for an intermittent open in the circuit.


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


No


4. CHECK THE (F202) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN OR SHORT


1. Reconnect the PCM C1 harness connector with the GPEC Adaptor connected in line.
2. Turn the ignition on.
3. Using a 12 volt test light connected to ground, probe the (F202) Fused Ignition Switch Output circuit at the GPEC Adaptor.
4. Check the circuit with the ignition on, engine running position, and during cranking.
5. Wiggle test each circuit during the test to check for an intermittent open in the circuit.


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


No


5. CHECK THE (F342) FUSED ASD RELAY OUTPUT CIRCUIT FOR AN OPEN OR SHORT


1. Remove the ASD/Main Relay.
2. Connect a fused jumper wire between terminals 30 and 87.
3. Using a 12-volt test light connected to ground, check the (F342) Fused ASD Relay Output circuit at the GPEC Adaptor.


Does the test light illuminate brightly?

Yes


No


6. CHECK THE (D65) CAN C BUS (+) CIRCUIT FOR AN OPEN


1. Turn the ignition off.
2. Disconnect the TIPM C1 harness connector.
3. Measure the resistance of the (D65) CAN C Bus (+) circuit between the TIPM C2 harness connector and the GPEC Adaptor.


Is the resistance below 5.0 Ohms?

Yes


No


7. CHECK THE (D64) CAN C BUS (-) CIRCUIT FOR AN OPEN


1. Measure the resistance of the (D64) CAN C Bus (-) circuit between the TIPM C2 harness connector and the GPEC Adaptor.


Is the resistance below 5.0 Ohms?

Yes


No