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
If equipped, the following actions occur:
| • | The EBCM disables the ABS/TCS for the duration of the ignition cycle. |
| • | The ABS indicator turns ON. |
| • | The Traction Off indicator turns ON. |
| • | The message center displays the Service Traction System message. |
| • | The EBCM will not send serial data messages. |
| • | The EBCM will not send the requested torque output to the PCM. |
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 | |||||
2 |
Important: Removing battery voltage or ground from the EBCM will result in the
following conditions:
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 |
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 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
