P1381

Diagnostic Chart:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) receives rough road information from the Electronic Brake Control Module (EBCM) or the Electronic Brake And Traction Control Module (EBTCM) on the Class 2 serial data circuit. The PCM uses the rough road information to enhance the misfire diagnostic by distinguishing crankshaft speed variations caused by driving on rough road surfaces from variations caused by true misfires. The EBCM or EBTCM transmits rough road information based on inputs from the wheel speed sensors. If a loss of communication occurs which causes the PCM not to receive rough road information while DTC P0300 is requesting the Malfunction Indicator Lamp (MIL), DTC P1381 will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine load is less than 87 percent.
^ The engine speed is less than 5,000 RPM.
^ The vehicle speed is more than 10 mph.
^ A misfire DTC is occurring and requesting the MIL to be illuminated.

CONDITIONS FOR SETTING THE DTC
The PCM detects a loss of communication with the EBCM or EBTCM for at least 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ The current DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL diagnostic trouble code.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.

Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to set occurs. This may assist in diagnosing the condition.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step ensures that the EBCM/EBTCM is capable of transmitting serial data.