P1381

Schematic:

CIRCUIT DESCRIPTION
This diagnostic will detect a loss of serial communication from the Electronic Brake Control Module (EBCM) to the control module. This serial communication is essential in order to distinguish misfire from a rough road condition.

CONDITIONS FOR RUNNING THE DTC
^ Misfire DTC is active
^ MIL is requested
^ No rough road ABS data information is available

CONDITIONS FOR SETTING THE DTC
A serial data malfunction is preventing the VCM from receiving rough road detection data.

ACTION TAKEN WHEN THE DTC SETS
^ The control module stores the DTC in history after the first failure but will not illuminate the Malfunction Indicator Lamp (MIL).
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles.
^ A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.
^ Use the scan tool Clear Information function.

An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections in Diagrams.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagrams.

Diagnostic Chart:

TEST DESCRIPTION
The number below refers to the step number on the diagnostic table.
3. This step isolates an open serial data circuit from the EBCM system.