For 1990-2009 cars only
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 Descriptor
DTC C0285: Brake Fluid Flow Switch Circuit LowDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Brake Fluid Level Sensor Signal | C0285 | -- | -- | -- |
Brake Fluid Flow Sensor Signal | C0285 | -- | -- | -- |
Brake Fluid Flow Sensor Ground | C0285 | -- | -- | -- |
Circuit/System Description
The electronic brake control module (EBCM) monitors the function of the brake fluid flow switch to assure that the switch opens and closes properly.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM detects a closed brake fluid flow switch for greater than 1.6 seconds.
Action Taken When the DTC Sets
| • | The brake warning indicator illuminates. |
| • | A fast audible chime turns ON. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | Ensure the power steering fluid is full and that the power steering belt is in good condition with proper tension. Any failure in the power steering system which effects steering or brake assist may cause this DTC to set. |
| • | Ensure the power brake system is operating properly. Perform the Brake Assist System Diagnosis. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Inspect the master cylinder reservoir for the proper brake fluid level.
| ⇒ | If brake fluid level is low, refer to Hydraulic Brake System Diagnosis and Diagnostic Aids. |
Circuit/System Testing
Important: This test should only be performed if brake fluid is not low.
- With the park brake released and the ignition OFF, disconnect the brake fluid level switch connector. Ignition ON, verify Brake indicator lamp on IPC is illuminated.
- Ignition ON, observe the scan tool Brake Fluid Level Status parameter in EBCM. Verify parameter is OK.
- Ignition OFF, disconnect the power brake booster fluid flow switch terminal A harness connector.
- Engine ON, idle for 10 seconds. Verify if DTC C0285 resets.
- If all circuits test normal, replace the EBCM.
| ⇒ | If the Brake indicator lamp is not illuminated, replace the brake fluid level switch. |
| ⇒ | If the Brake Fluid Level Status parameter is Low, repair short to ground in terminal B brake fluid level switch signal circuit. |
| ⇒ | If DTC C0285 resets, test the brake booster fluid flow switch signal circuit terminal A for a short to ground and test the park brake booster fluid flow switch ground circuit terminal B for a short to ground. If the circuits test normal, replace the EBCM. |
| ⇒ | If DTC C0285 does not reset, replace the power brake booster fluid flow switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
