Deutz-Fahr 592 – Engine Control Unit (ECU), specifically EMR3 and EMR4: Fuel Metering Unit Cable Break

The Engine Control Unit (ECU) has detected an open load or current below normal in the electrical circuit for the fuel metering unit. This indicates a break or disconnection in the wiring to the valve that regulates fuel flow to the high-pressure pump. This failure prevents the ECU from correctly controlling the amount of fuel entering the high-pressure common rail system, resulting in improper fuel delivery, rough running, power loss, or complete engine shutdown.

• Deutz TCD 2.9 L4
• Deutz TCD 3.6 L4
• Deutz TCD 4.1
• Deutz 1011 series
• Deutz 2011 series
• Genie lifts with Deutz D 2.9 L4
• Genie lifts with Deutz TD 2.9 L4

1. 1

   Visually inspect the wiring harness and connector leading to the fuel metering unit (MProp valve) for chafing, breaks, or misplaced routing.

2. 2

   Disconnect the harness from the fuel metering unit and inspect the connector pins for widening, corrosion, or wear caused by vibration.

3. 3

   Check the wiring harness for continuity and for short circuits to the battery or ground to locate any open load or broken wire.

4. 4

   Measure the resistance of the fuel metering unit's coil using a multimeter (normal reading should be around 3 ohms).

5. 5

   Ensure the main engine ECU connectors are secure and free of corrosion.

6. 6

   Perform a functional test by unplugging the metering unit to see if the engine attempts to fire (in some systems, this causes the high-pressure pump to go to maximum pressure).

1. 1

   Prepare machine

   Turn the machine's ignition off and disconnect the battery before starting any electrical repairs.

2. 2

   Locate and disconnect

   Locate the fuel metering unit on the high-pressure common rail fuel pump and disconnect the electrical connector. Perform the diagnostic checks on the connector and the unit's resistance.

3. 3

   Repair connector

   If the connector is damaged or the pins are loose, replace the connector pigtail using a repair kit containing a new harness connector and terminals.

4. 4

   Repair wiring harness

   If the wiring harness shows signs of an open circuit or cable break, repair the specific wire or replace the relevant section of the engine harness.

5. 5

   Replace fuel metering unit

   If the wiring and connector are in good condition, remove the retaining screws holding the fuel metering unit to the pump. Clean the mounting surface and install the new unit with a new gasket or O-ring. Torque retaining screws to manufacturer specifications.

6. 6

   Reconnect and clear codes

   Securely attach the electrical connector, reconnect the battery, and turn the ignition on. Use a diagnostic tool (such as Deutz SerDia or Jaltest) to clear inactive fault codes.

7. 7

   Verify repair

   Start the engine and check for correct operation to ensure the fault code does not reappear.