Case IH 19207 – Engine Control Module (ECM) or Dosing Control Unit (DCU): Short circuit to ground at low side power stage of external actuator relay 1

The control module has detected that the electrical circuit controlling "External Actuator Relay 1" is shorted to ground on the low side (the ground-switched side of the relay control circuit).

• Tier 4b
• Puma
• Magnum
• Steiger
• combines
• sprayers

1. 1

   Check battery voltage to ensure it is within normal operating limits (voltage fluctuation cause)

2. 2

   Inspect the wiring harness between the ECM/DCU and External Actuator Relay 1 for chafed wires, pinched harnesses, or exposed copper shorting to the chassis (wiring short cause)

3. 3

   Remove External Actuator Relay 1 and test it for internal short circuits (relay failure cause)

4. 4

   Disconnect the connected actuator to see if the short-to-ground condition clears (internal actuator short cause)

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical damage during testing.

2. 2

   Locate the Relay

   Locate "External Actuator Relay 1" in the engine harness or main power distribution box.

3. 3

   Isolate the Short

   Disconnect the relay and use a multimeter to check for continuity to ground on the low-side control wire leading back to the ECM/DCU.

4. 4

   Repair Wiring

   If the wire is shorted to ground, trace the harness and repair the damaged section of the wiring.

5. 5

   Replace the Relay

   If the wiring tests good but the relay is internally shorted, replace the relay.

6. 6

   Replace the Actuator

   If the relay and wiring are intact, the fault lies within the connected actuator. Replace the connected actuator.

7. 7

   Clear Codes

   Reconnect the battery, turn the key on, and use the CNH EASy diagnostic tool (or equivalent) to clear the fault code and verify the repair.