P1689

Schematic:

CIRCUIT DESCRIPTION
The Electronic Brake And Traction Control Module (EBTCM) controls the PWM signal on the Desired Torque circuit while monitoring the wheel speed sensors to detect slippage. The PCM monitors the PWM signal and reduces engine torque as needed by retarding ignition timing, decreasing boost duty cycle, increasing air/fuel ratio, or, in severe cases, shutting OFF up to three fuel injectors. The PCM sends a PWM signal to the Electronic Brake And Traction Control Module (EBTCM) on the delivered torque circuit informing the EBTCM of response made to the desired torque signal. A problem with the delivered torque circuit should cause DTC P1689 and ABS/TCS DTC 76 to set and traction control to be disabled. Refer to ABS/TCS for further information.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
^ An improper voltage level has been detected on the output circuit which controls the traction control delivered torque output.
^ The above conditions present for at least 30 seconds.

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 Failure Records data only. This 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.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
Inspect for the following:

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Diagrams.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault. Refer to Wiring Repairs in Diagrams.
^ Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION

Steps 1 - 9:

Steps 10 - 16:

The numbers below refer to the step numbers on the diagnostic table.
2. Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.
3. Tests for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps.
Also tests for a component that is going open while being operated, resulting in a measured current of 0 milliamps.
4. Tests for a short to voltage on the control circuit.
15. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.