Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the U1412-IMPLAUSIBLE VEHICLE SPEED SIGNAL RECEIVED active at this time?

Yes
1. Go To step 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT IS ACTIVE
Continue reading DTCs.

Is the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT ACTIVE at this time?

Yes
1. Refer to the Diagnostic Procedure for the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT.
No
1. Go To step 3).
3) ABS MODULE IS ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.

Verify that the ABS Module active on the bus.

Is the ABS Module active on the bus?

Yes
1. Go To step 4).
No
1. (Refer to ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS ) for No Response diagnostic procedures.
2. Perform BODY VERIFICATION TEST - VER 1 .
4) ACTIVE DTCS IN THE FCM
With the scan tool, select ECU View and select FCM.

With the scan tool, read active DTCs.

Is the U0001-NO COMMUNICATION ON THE CAN C BUS CIRCUIT ACTIVE in the FCM at this time?

Yes
1. Replace the ABS Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .