P1573

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The PCM uses the UART serial data line (CKT 800) to communicate with various other components and systems within the vehicle. If the PCM does not receive data from the Electronic Brake and Traction Control Module (EBTCM), the PCM will store DTC P1573 indicating loss of communication with the ABS/TCS system.

CONDITIONS FOR SETTING THE DTC

^ The PCM has detected a PCM - EBTCM communication error for 0.5 second.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).

^ The PCM will store conditions which were present when the DTC set as Fail Records data only. The information will not be stored as Freeze Frame data.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

^ DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS

An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Check for the following conditions:

^ Poor Connection or Damaged Harness. Inspect the vehicle wiring harness for an open or short to ground in CKT 800, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.

^ Intermittent Test - Observe ABS data on the scan tool while moving harness and related connectors. Refer to UART Data Line in Electrical Diagrams for a description of CKT 800 and devices using the UART serial data line. If failure is induced, the scan tool data will stop updating. This may help to isolate the location of the malfunction.

^ If the above items have been checked and no problem is found but DTC P1573 continues to set, replace the PCM.

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

TEST DESCRIPTION

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. Checks to see if the Electronic Brake and Traction Control Module (EBTCM) is able to transmit data and ensures that CKT 800 to the EBTCM is not open.