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 C0126 00: Low Brake Fluid IndicatedDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Brake Fluid Level Signal | C0126 00 | 1 | 1 | -- |
Park Brake Signal | 1 | 1 | 1 | -- |
Ground | -- | 1 | -- | -- |
1. Brake Warning Indicator Malfunction | ||||
Circuit/System Description
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the instrument panel cluster (IPC) sees the brake fluid level switch input closed, it turns ON the Red Brake Warning indicator and sends a serial data message to the electronic brake control module (EBCM) that the brake fluid level is low.
Conditions for Running the DTC
Ignition ON.
Conditions for Setting the DTC
| • | Low brake fluid is detected. |
| • | A short to ground exists on the signal circuit. |
Action Taken When the DTC Sets
| • | The EBCM disables the antilock brake system (ABS)/traction control system (TCS) dynamic rear proportion (DRP) and vehicle stability enhancement system (VSES). |
| • | A DIC message and/or a warning indicator may be displayed. |
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. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Brake Warning System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Inspect for proper brake fluid level, the fluid level should be at or above the proper level.
- Ignition ON, observe the scan tool IPC Brake Fluid Level Switch parameter. The reading should be OFF.
| ⇒ | If low, refer to Brake Fluid Loss. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the brake fluid level switch.
- Test for less than 5 ohms between the ground circuit terminal 2 and ground.
- Ignition ON, test for 4.8 - 5.2 volts between the 5 volt reference circuit terminal 1 and ground.
- If all circuits test normal, test or replace the brake fluid level switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | 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 IPC. |
| ⇒ | If greater than the specified range, test the 5 volt reference circuit for a short to voltage. If the circuit tests normal, replace the IPC. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for IPC replacement, setup, and programming |
