Circuit Description
The EBCM provides power (5 volts) and ground to the accelerometer through 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 DTC
| • | DTC C1297 can set anytime after initialization is completed. |
| • | A malfunction exists if the EBCM detects a short to ground in the accelerometer power circuit (CKT 9Q01), or a short to ground in the accelerometer signal circuit (CKT 9S01). |
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | The ABS disables. |
| • | The ABS warning indicator turns ON. |
| • | If failure occurs during an ABS event, ABS is disabled after the completion of the ABS event. |
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
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
Any circuitry that is suspected of causing the intermittent complaint should be thoroughly checked for improper mating, improperly formed or damaged terminals, poor terminal to wiring connections, or physical damage to the wiring harness.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Diagnostic System Check | |
2 |
Do not start the engine. Is this DTC set as current ? | -- | ||
3 |
Is the resistance measured within the range specified in the Value(s) column? | OL (Infinite) | ||
4 | Using J 39200 , measure the resistance between the EBCM harness connector C1 terminal D2 and ground. Is the resistance measured within the range specified in the Value(s) column? | OL (Infinite) | ||
5 |
Is the accelerometer voltage output approximately 2.5 volts (vehicle not in motion). | -- | ||
6 |
Does this DTC reset as current? | -- | ||
7 |
Does this DTC reset as current or history during these drive cycles? | -- | ||
8 | Repair the short to ground in CKT 9S01. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
9 | Repair the short to ground in CKT 9Q01. Is the repair complete? | -- | Go to Diagnostic System Check | -- |
10 | Replace the accelerometer. Refer to Lateral Accelerometer Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | -- |
11 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | -- |
12 | Malfunction not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC. Is the action complete? | -- | System OK | -- |
