PRNDL Inoperative No Crank Start At Times DTC C0268 - keywords automatic blank crank display inoperative invalid IP IPC no nocrank nostart start

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A Customer may comment at times of a no crank no start, PRNDL display may blank on the IPC. Further inspection with the Tech 2 may reveal DTC C0268 stored in history. Prior to starting the vehicle, the PCM needs to see the Park input. The PRNDL display is sent from the PCM to the IPC via Class 2 communication. The PCM will send the proper indicator based on circuits 771, 772, 773 and 776 (SI Document 1550777) from the Transmission range switch to the PCM. If this input is not received DTC C0268 will set, the vehicle will not crank, start or display PRNDL. This may be the result of the Transmission Range Switch. This will only affect vehicles equipped with automatic transmissions.

Note: DTC C0268 is a referenced in SI as a loss of communication. This should be viewed as a loss of data and not communication.

Monitor the Transmission Range Data in the PCM to be sure the PCM receives the correct transmission position from the Transmission Range Switch. Using the Tech 2, monitor Transmission Data Display. Specifically, monitor "Tr. Sw." Data (This data is the PNP switch in the schematics SI Document 1550777). If the "Tr. Sw." Data display "invalid" or is blank with no value, inspect the Transmission Range Switch for integrity. Further, refer to SI document 1550777. Voltage drop circuits 771, 772, 773 and 776 at the PCM with a DVM for integrity.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.