Circuit 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 grounded, it turns ON the red Brake indicator and sends a serial data message to the electronic brake control module (EBCM) that tells the EBCM that the brake fluid level is low.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1247 Low Brake Fluid Detected
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a serial data message from the IPC indicating that the brake fluid level is low.
Action Taken When the DTC Sets
| • | The EBCM disables the Traction Control System (TCS) until the DTC becomes a history DTC. |
| • | The red Brake warning indicator turns ON. |
| • | The Traction Off indicator turns ON. |
| • | The message center displays the Service Traction System message. |
| • | The Antilock Brake System (ABS) remains functional. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The 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 Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 | Inspect the brake fluid level. Is the brake fluid level OK? | Go to Step 3 | Go to Brake Fluid Loss |
3 |
Does the scan tool indicate that the Low Brake Fluid parameter is Off? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 4 |
4 |
Does the scan tool indicate that the Low Brake Fluid parameter is Off? | Go to Step 6 | Go to Step 5 |
5 | Test the signal circuit of the brake fluid level switch 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 8 | Go to Step 7 |
6 | Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement . Did you complete the repair? | Go to Step 8 | -- |
7 | Replace the IPC. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the repair? | Go to Step 8 | -- |
8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
