Circuit Description
When the master cylinder is low on brake fluid the brake fluid level indicator switch grounds the circuit and turns on the RED brake indicator in the instrument cluster, then the instrument cluster sends a class 2 message to the EBCM. If the low brake fluid message is sent from the IPC to the EBCM, TCS will be disabled and a Diagnostic Trouble Code (DTC) sets.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a class 2 message from the instrument cluster.
Action Taken When the DTC Sets
| • | TCS is disabled. |
| • | TCS Indicator (TRAC OFF) is turned on. |
| • | RED Brake indicator is turned on. |
| • | Service Vehicle Soon indicator is turned on. |
Conditions for Clearing the DTC
Condition for DTC is no longer present or scan tool clear DTC function is used.
Diagnostic Aids
| • | Possible causes for DTC C1247 to set are: |
| - | Any leaks in hydraulic brake system (such as brake pipes, wheel cylinders, calipers, or master cylinder). |
| - | Brake fluid level indicator switch malfunction. |
| - | Brake fluid level indicator input circuit is short to ground. |
| • | It is very important that a thorough inspection of the wiring, connectors, and the hydraulic brake system components be performed. Failure to carefully and fully inspect wiring, connectors, and hydraulic brake system components may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
| • | If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the ABS Diagnostic System Check? | -- | ||
2 | Inspect the Master Cylinder brake fluid level. Is the brake fluid at the proper level in the Master Cylinder reservoir? | -- | Go to Brake Fluid Leak | |
3 |
Does the scan tool indicate that the brake fluid level is Normal? | -- | Go to Testing for Intermittent Conditions and Poor Connections | |
4 |
Does the scan tool indicate that the brake fluid level is Normal? | -- | ||
5 | Test the signal circuit of the brake fluid level indicator switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | ||
6 | Inspect for poor connections at the harness connector of the brake fluid level indicator switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
7 | Inspect for poor connections at the harness connector of the IP. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 | Replace the Brake Fluid Level Indicator switch. Refer to Brake Fluid Level Indicator Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | -- | -- | |
9 | Replace the IP. Refer to Instrument Cluster Replacement . Did you complete the replacement? | -- | -- | |
10 |
Does the DTC reset? | -- | System OK |
