DTC B334: Loss Of ECM Serial Data: Description

Code B334 will set if the ignition is on and the BCM is not able to exchange data with the ECM (if any other communication codes are stored along with B334. When this is the only communication code stored, the problem must be one of the following: An open CKT 800E and 800F or 800E and 800D, a faulty ECM or ECM Calpack.

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 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.