C0191

DTC C0191

Circuit Description

The ignition 1 circuit supplies 12 volts to the longitudinal accelerometer. When the vehicle is not moving, or is being driven at a constant, steady speed, longitudinal acceleration is 0 m/sec/sec (0 ft/sec/sec), and the longitudinal accelerometer signal voltage is very near 2.5 volts. This is referred to as longitudinal accelerometer bias voltage. Vehicle acceleration or deceleration causes the longitudinal accelerometer signal voltage to increase or decrease. The harder the acceleration or deceleration, the greater the change in signal voltage.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0191 All Wheel Drive (AWD)/Four Wheel Drive (4WD) Reference Accelerometer Circuit

Conditions for Running the DTC

Both of the conditions listed below may be required to set the DTC.

* The ignition is ON.
* The vehicle is accelerated rapidly to a speed greater than 11 km/h (7 mph) before decelerating rapidly to a stop.

Conditions for Setting the DTC

Any of the following conditions may cause the DTC to set.

* Open longitudinal accelerometer circuitry is detected.
* Shorted longitudinal accelerometer circuitry is detected.
* An erratic longitudinal accelerometer signal is detected.
* The electronic brake control module (EBCM) detects that the longitudinal accelerometer sensor signal does not correspond with signals from other sensors.

Action Taken When the DTC Sets

* The EBCM disables the Antilock Brake System (ABS).
* The ABS indicator turns ON.
* The ABS fault message is displayed.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents, Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Diagnostic Aids.

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

* Testing for Electrical Intermittents
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
* Connector Repairs

Step 1 - Step 9:

Step 10 - Step 15: