For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

### Circuit Description

When EBCM relay is activated (turned on) voltage is supply to valve solenoids and pump motor. This DTC identifies a malfunction with the EBCM loosing ground or battery, or when battery is disconnected while running.

### Conditions for Running the DTC

The ABS/TCS conditions are normal.

### Conditions for Setting the DTC

DTC C1254 is set when an running reset occurs. A running reset is when the vehicle is running and functions are normal then suddenly a loss of power or ground connection occurs to the EBCM.

### Action Taken When the DTC Sets

• | ABS/TCS is disabled.

• | ABS/TCS Indicators are turned on.

### Conditions for Clearing the DTC

• | Condition for DTC is no longer present and scan tool clear DTC function is used.

• | 100 ignition cycles have passed with no DTCs detected.

### Diagnostic Aids

• | Possible causes for DTC C1254 to set are:

- | Running reset occurred.

- | Loss of EBCM ground.

- | Sudden drop in voltage.

- | Poor or loose grounds connections.

- | Poor or loose power connections.

- | Battery disconnected due to corrosion or loose battery terminals.

- | Internal EBCM malfunction.

• | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors 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? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Turn OFF the ignition.
2. Disconnect the EBCM harness connector.
3. Install the J 39700 universal breakout box using the J 39700-99 cable adapter to the EBCM harness connector only.
4. Test the module ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 3

3 | Has the battery been disconnected recently? | -- | Go to Step 8 | Go to Step 4
4 | Test the charging system. Refer to Diagnostic System Check - Engine Electrical in Engine Electrical. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 5
5 | Inspect for poor connections/terminal tension at the EBCM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6
6 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 7

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

7 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement Did you complete the repair? | -- | Go to Step 8 | --
8 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK