Jump to content
  • P0478 High Voltage On The Engine Brake Driver

       (0 reviews)

    Mopar1973Man

    P0478 HIGH VOLTAGE ON THE ENGINE BRAKE DRIVER

    When Monitored and Set Condition:

    When Monitored: When the ignition is on.
    Set Condition: When the signal from the engine brake driver output does not match the signal from the engine
    brake driver feedback.

    POSSIBLE CAUSES

    • RELAY LOOSE
    • ENGINE BRAKE DRIVER CONTROL CIRCUIT SHORTED TO VOLTAGE
    • ENGINE BRAKE RELAY
    • INTERMITTENT CONDITION
    • ECM

    DIAGNOSTIC PROCEDURE

    1. Ignition on, engine not running. With the DRBIII®, actuate the Engine Brake Driver Relay. Can you hear the Relay clicking?
      Yes --> Go To 2
      No --> Go To 3
    2. While the relay is clicking, wiggle the wiring harness and connectors. Does this interrupt the clicking?
      Yes --> Repair the loose connection. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
      No --> Go To 3
    3. Turn the ignition off. Remove the Engine Brake Driver Relay. Disconnect the ECM harness connectors. Check connectors - Clean/repair as necessary. Measure the voltage of the Engine Brake Driver Control Circuit between the relay terminal and battery negative. Is the voltage less than 1 volt?
      Yes --> Go To 4
      No --> Repair Engine Brake Driver Control Circuit shorted to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
    4. Measure the resistance between terminals 85 and 86 of the engine brake relay. Is the resistance less than 10 ohms?
      Yes --> Replace the engine brake relay. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
      No --> Go To 5
    5. Reconnect the ECM harness connectors. Reinstall the Engine Brake relay. Ignition on, engine not running. While monitoring with the DRBIII®, remove the Engine Brake Driver Relay. Did P0477 set?
      Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
      No --> Replace the ECM. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

    User Feedback

    There are no reviews to display.


×
×
  • Create New...

Advertisements and Ad Blockers

Mopar1973Man.Com uses the income from advertisers to pay the bills on the website. Please whitelist your ad blockers for Mopar1973Man.Com this will allow advertisements to display on our pages but allows you to still block ads on the other websites you visit. 

 

image.png

I will whitelist Mopar1973Man.Com