C1298

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Circuit Description
The Electronic Brake Control Module (EBCM) provides power (5 volts) and ground to the accelerometer through Circuit (CKT) 9Q01 and CKT 9R01 respectively. The accelerometer converts the change in vehicle motion, or inertia, into a voltage signal. This signal is sent to the EBCM through CKT 9S01.
The accelerometer provides additional vehicle speed reference to the EBCM. The voltage signal ranges, from 2.4 to 2.6 volts at zero speed change (constant motion). The accelerometer voltage signal drops when the vehicle is under acceleration. The accelerometer voltage signal increases when the vehicle is under deceleration.

Conditions for Setting the Diagnostic Trouble Code (DTC)
- This DTC can be set anytime after initialization is completed.
- A malfunction exists if the EBCM detects an open or a short to voltage in the accelerometer signal circuit (CKT 9S01).

Action Taken When the DTC Sets
- A malfunction DTC stores.
- The Antilock Brake System (ABS) disables.
- The ABS warning indicator turns ON.

Conditions for Clearing the DTC
- The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
- 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition off.

Diagnostic Aids
The following conditions may cause an intermittent malfunction:
- A poor connection
- Rubbed-through wire insulation
- A broken wire inside the insulation
- Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malt unction.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal-to-wiring connections
- Physical damage to the wiring harness