• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
IGN I | C0901 | C0901 | -- | -- |
Ground | -- | C0901 | -- | -- |
The electronic brake control module (EBCM) monitors the ignition voltage level available on the ignition 1 circuit. A low voltage condition prevents the system from operating properly. If the EBCM detects low voltage on the ignition 1 circuit, DTC C0901 will set.
• | The ignition is ON. |
• | The vehicle speed is greater than 3 km/h (1.8 mph) |
The EBCM detects that the ignition voltage is less than 6.5 volts for 7 seconds.
The BRAKE indicator turns ON.
• | The DTC will pass when the ignition voltage is greater than 6.5 volts for 1 second. |
• | The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive ignition cycles. |
A low voltage DTC in multiple modules indicates a concern in the charging system.
Antilock Brake System Schematics
Control Module References for scan tool information
• | Terminal C X1 |
• | Terminal 1 X2 |
• | Terminal 32 X2 |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
• | Terminal A X1 |
• | Terminal 16 X2 |
• | Terminal 47 X2 |
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for EBCM replacement, setup, and programming.