For 1990-2009 cars only
Diagnostic Information
| • | 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 Descriptor
DTC C0901: Device 2 Voltage Low - EBCMDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Signal | C0901 | C0901 | -- | -- |
Ground | -- | C0901 | -- | -- |
Circuit/System Description
The electronic brake control module (EBCM) monitors the ignition 1 voltage (IGN1) level available for system operation. A low voltage condition prevents the system from operating properly.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | Ignition 1 (IGN1) voltage to the EBCM is less than 6.5 volts for 7 seconds. |
| • | Vehicle speed is greater than 3 km/h (2 mph). |
Action Taken When the DTC Sets
The brake warning indicator turns ON.
Conditions for Clearing the DTC
| • | The DTC passes when the condition for the DTC is no longer present. |
| • | The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
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 Verification
- Engine running, accessories OFF, measure and record the voltage at the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.
- Observe the scan tool EBCM Battery Voltage parameter. The reading should be between 12.60 and 15.00 volts.
| ⇒ | If not within the specified range, refer to Charging System Test . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the EBCM.
- Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminals listed below and ground:
- Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground:
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 21 and ground.
- If all circuits test normal, replace the EBCM.
| • | Terminal 2 |
| • | Terminal 3 |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| • | Terminal 1 |
| • | Terminal 4 |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for EBCM replacement, setup, and programming.
