2012 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

U0298-LOST COMMUNICATION WITH DC TO DC CONVERTER CONTROL MODULE "A"

U0298-LOST COMMUNICATION WITH DC TO DC CONVERTER CONTROL MODULE "A"

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



Possible Causes

CAN BUS OPEN OR SHORTED CONDITION
DC/DC CONVERTER 1
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).


1. DTC IS ACTIVE


1. Ignition on, engine not running.
2. With the scan tool, Clear DTCs in the PCM.
3. Monitor the scan tool for at least two minutes.
4. Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time.
5. Start the engine.
6. Allow the engine to reach normal operating temperature.
7. With the scan tool, select View DTCs.


Is the status Active for this DTC?

Yes


No


2. OTHER LIN BUS COMMUNICATION DTCs


1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.


Are there any Communication DTCs logged for the Generator or Intelligent Battery Sensor?

Yes


No


3. CHECK THE (D509) LIN BUS CIRCUIT FOR A SHORT TO GROUND



1. Turn the ignition off.
2. Disconnect the IBS harness connector.
3. Disconnect the PCM C1 harness connector.
4. Disconnect the Generator C2 harness connector.
5. Disconnect the DC to DC Converter C1 harness connector.
6. Disconnect the DC to DC Converter C2 harness connector.
7. Measure the resistance between ground and the (D509) LIN BUS circuit at the IBS harness connector.


Is the resistance above 10k Ohms?

Yes


No


4. CHECK THE (D509) LIN BUS CIRCUIT FOR AN OPEN/HIGH RESISTANCE



1. Measure the resistance of the (D509) LIN BUS circuit between the IBS harness connector and the PCM C1 harness connector.


Is the resistance below 5.0 Ohms?

Yes


No


5. DC/DC CONVERTER


1. Turn the ignition off.
2. Replace DC/DC Converter 1 in accordance with the service information.
3. Reconnect all of the disconnected harness connectors.
4. Turn the ignition on.
5. With the scan tool, erase DTCs in the PCM.
6. Cycle the ignition on and off several times, leaving the ignition on for at least 20 seconds during each ignition cycle.
7. Turn the ignition on.
8. With the scan tool, select View DTCs.


Did the DTC return?

Yes


No


6. POWERTRAIN CONTROL MODULE


1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the DC/DC Converter and the Powertrain Control Module.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.


Were any problems found?

Yes


No


7. DC/DC CONVERTER


1. Turn the ignition off.
2. Replace the DC/DC Converter in accordance with the service information.
3. Reconnect all of the disconnected harness connectors.
4. Turn the ignition on.
5. With the scan tool, erase DTCs in the PCM.
6. Cycle the ignition on and off several times, leaving the ignition on for at least 20 seconds during each ignition cycle.
7. Turn the ignition on.
8. With the scan tool, select View DTCs.


Did the DTC return?

Yes


No


8. POWERTRAIN CONTROL MODULE


1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the DC/DC Converter and the Powertrain Control Module.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.


Were any problems found?

Yes


No