Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C0870 00: Device Voltage Reference Output 1 CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5 volt Reference | C0870 00 | C0870 00 | C0870 00 | -- |
Low Reference | -- | C0870 00 | -- | -- |
Circuit/System Description
The electronic brake control module (EBCM) supplies voltage to the brake pressure sensor, steering angle sensor, and yaw rate/lateral accelerometer sensor. This voltage is monitored by the EBCM for an over or under voltage condition.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The sensor supply voltage is less than 4.8 volts. |
| • | The sensor supply voltage is greater than 5.2 volts. |
Actions Taken When the DTC Sets
| • | The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | The Stabilitrak indicator illuminates. |
Conditions for Clearing the DTC
| • | A current DTC clears when the diagnostic runs and passes. |
| • | A history DTC clears after 100 consecutive ignition cycles, if no failures are reported by this diagnostic. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
Important: The brake pressure sensor and steering angle sensor share the 5 volt reference and the low reference circuits. Test these sensors as part of the circuit when performing this diagnostic.
- Ignition OFF, disconnect the harness connector at the yaw and lateral accelerometer sensor.
- Ignition OFF, test for less than 5 ohm between the low reference circuit terminal D and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal B and ground.
- If all circuits test normal, test or replace the yaw and lateral accelerometer sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
