B334

Code B334:

Display Circuit:

DESCRIPTION:

Code B334 will set if the ignition is on and the BCM is not able to exchange data with the PCM/ECM (if any other communication codes are stored along with B334, see Multiple Intermittent Codes chart). When this is the only communication code stored, the problem must be one of the following:

1. An open in CKT 800 between the PCM/ECM and Programmer and a second open between the PCM/ECM and The CCDIC.
2. A faulty PCM/ECM or PCM/ECM MEM-CAL.

During the time the failure is present, a fail soft value equal to 100°C will be used for the coolant temperature, the cooling fans will be commanded to high speed, and no PCM/ECM diagnostic information will be available for display. Also, while in the service diagnostic mode, this code will remain active, always checking for proper operation.


TEST DESCRIPTION: The numbers below refer to circled numbers on diagnostic chart.

1. This step checks for intermittent operating conditions.

2. This step checks to see if the open is in CKT 800 between the PCM/ECM and CCDIC. If CCDIC blanks, the data line connections are good.

3. Since the climate control display did not blank in the last step, an open exists between the CCDIC and the PCM/ECM in the data circuit. Grounding B8 will isolate if the open is in the CKT or internal to the CCDIC.

NOTE ON INTERMITTENTS:

If only code B334 is stored as "History," check the power and grounds for intermittent faults and 800 for an intermittent open circuit. If PCM/ECM code E052 history is also set, go to that diagnostic chart.