For 1990-2009 cars

### Circuit Description

The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the EBCM sees the brake fluid level switch input grounded, it sends a serial data message to the IPC that tells the IPC that the brake fluid level is low. The IPC then turns ON the red Brake indicator.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

The brake fluid level sensor signal is less than 1.87 volts for 2 seconds.

### Action Taken When the DTC Sets

The red Brake warning indicator turns ON.

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

• | The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

Inspect the master cylinder reservoir for the proper brake fluid level.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Brake Warning System Schematics Connector End View Reference: Hydraulic Brake Connector End Views
1 | Did you perform the Hydraulic Brake Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Hydraulic Brakes
2 | Inspect the brake fluid level. Is the brake fluid level OK? | Go to Step 3 | Go to Brake Fluid Loss
3 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Disconnect the brake fluid level switch.
4. Use the scan tool to clear DTCs.

Does the scan tool indicate that DTC C1247 has reset?

Go to Step 4

Go to Step 5

4 | Test the brake fluid level sensor signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 6
5 | Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement . Did you complete the repair? | Go to Step 7 | --
6 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement in Antilock Brake System. Did you complete the repair? | Go to Step 7 | --
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2