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 C0286 : Brake Fluid Flow Switch Circuit HighDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Power Brake Booster Fluid Flow Switch Signal | -- | C0286 | C0286 | -- |
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 open brake fluid flow switch for greater than 4.4 seconds.
Action Taken When the DTC Sets
| • | The brake warning indicator illuminates. |
| • | A fast rate audible chime turns ON. |
Conditions for Clearing the DTC
The condition for setting the DTC are no longer present.
Diagnostic Aids
| • | This DTC may be caused by a fluid flow switch that sticks open intermittently. |
| • | Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. |
| • | The ground circuit 151 of the Park Brake Booster Fluid Flow Switch should be checked for an intermittent or open. |
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Clear the DTCs, Engine ON, allow the engine to idle for 10 seconds. Engine OFF for 10 seconds, Ignition ON, the DTC should set.
Circuit/System Testing
- Ignition OFF, disconnect the power brake booster fluid flow switch harness connector of the EBCM.
- Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal B of the park brake booster fluid flow switch and ground.
- Engine ON at idle, verify that a test lamp blinks ON then OFF, connected between the power brake booster fluid flow switch signal terminal 28 of the EBCM and a good ground.
- If all circuits test normal, replace the park brake booster fluid flow switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test between the park brake booster fluid flow switch signal circuit terminal A and splice 111 for an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | If the test lamp illuminates in a blinking manner ON then OFF, test between the park brake booster fluid flow switch signal circuit terminal A and splice 111 for a short to voltage. If the circuit tests normal, replace the park brake booster fluid flow switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Important: After doing a EBCM replacement, use the scan tool to perform a Tire Size/Wheel Base Calibration procedure in EBCM special functions. Refer to Electronic Brake Control Module Replacement
| • | Control Module References for EBCM replacement, setup, and programming |
