P1644

Electrical Diagram:

CIRCUIT DESCRIPTION

The Electronic Brake and Traction Control Module (EBTCM) supplies 12.0 Volts on the Delivered Torque circuit to the PCM. The PCM toggles this 12.0 volt signal to a ground in order to produce a duty cycle signal. The signal is proportional to the amount of engine output torque reduction. In order to reduce engine output torque, the PCM reduces the amount of spark advance and in some cases the PCM disables a number of fuel injectors. This diagnostic test checks for a Delivered Torque signal failure. If the PCM does not receive the Delivered torque signal, this DTC sets.

CONDITIONS FOR SETTING THE DTC

^ The traction control has not failed.

^ The engine speed is greater than 500 RPM for 20 seconds.

^ The PCM does not receive the Delivered torque signal for 3 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 clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.

^ The PCM battery voltage is interrupted.

^ Use a scan tool in order to clear the MIL/DTC.

DIAGNOSTIC AIDS

The following may cause an intermittent:

^ Mis-routed harness

^ Rubbed through wire insulation

^ Broken wire inside the insulation

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

3. This step determines if the PCM is receiving the 12.0 volts from the EBTCM.

6. This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.