Fendt 1E.1.D7 – A051 - ECU, Engine Control Unit (EDC 7): Incorrect voltage for internal 5V reference source 1.

The engine control unit provides a 5-volt reference signal to power specific engine sensors. This code triggers when the voltage on the "Reference Source 1" circuit falls outside the expected operating range, usually due to a short circuit, a broken wire, or an internally shorted sensor pulling the voltage down.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario COM III (309, 310, 311, 312)
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III (922, 924, 927, 930, 933, 936)

1. 1

   Disconnect both the B090 (Oil Pressure) and B092 (Boost Pressure/Temperature) sensors.

2. 2

   Turn the ignition on and measure the supply voltage at the harness connectors for both sensors. It should read a steady 5.0 VDC.

3. 3

   If the 5V reference returns to normal when the sensors are unplugged, plug them in one at a time to isolate which sensor has an internal short pulling the voltage down.

4. 4

   If the voltage remains incorrect with both sensors unplugged, inspect the wiring harness between the sensors and the A051 (EDC 7) module for chafing, cable breaks, or a short to ground.

1. 1

   Locate the sensors

   Locate B090 (Oil Pressure Sensor) on the bottom left of the oil filter housing (requires removing the metal panel). Locate B092 (Boost Pressure/Temperature Sensor) on the front of the engine, on the charge air intake.

2. 2

   Repair wiring or replace sensor

   Repair any damaged wiring found in the harness. If the wiring is intact but a sensor is internally shorted, replace the faulty sensor.

3. 3

   Clear the fault code

   Clear EDC 7 engine faults from the engine control unit memory using the SERDIA diagnostic software (or FENDIAS) after the physical repair is completed.

4. 4

   Verify repair

   Cycle the ignition and start the tractor to ensure the 1E.1.D7 code does not return and that the tractor exits emergency/derate mode.