John Deere 1209.03 – Engine Control Unit (ECU): Exhaust Manifold Pressure Signal Out of Range High / Exhaust Gas Recirculation (EGR) High Pressure Side Sensor Fault (High Voltage)

The controller has detected that the voltage signal from the exhaust manifold pressure sensor (or EGR pressure sensor) is above the applicable normal range (typically greater than 5.5V). This usually indicates a short to power in the wiring harness or a failed sensor. When this code is active, engine power may be limited (limp mode) and active exhaust filter cleaning (regen) will be unavailable.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 3032E
• 4066R
• 6R Series
• 7R Series
• 8R Series
• 9R Series
• 204L
• 304L
• 310G
• 544K
• 710K
• 850K
• 350G
• 210G
• 50G
• 85G
• 7760 Cotton Picker
• S-Series Combines
• S650
• S670
• S770
• 7500A
• 8000A
• 8700A

1. 1

   Visual Inspection: Check the exhaust manifold pressure sensor (often located on top of the valve cover) and its wiring harness for physical damage, corrosion, or loose connections.

2. 2

   Cooling System: Check the cooling system and radiator for debris, as excessive heat can trigger related exhaust temperature/pressure faults.

3. 3

   Voltage Test: Use a multimeter to check the voltage at the sensor connector (5-volt supply, return/ground, and signal).

4. 4

   Harness Resistance Check: If the signal voltage is > 5.5V, check the VREF (reference voltage) circuit for a short to power. If the signal is completely lost or erratic, check for an open circuit or a short to ground.

1. 1

   Safety First

   Ensure the machine is in neutral, the parking brake is set, and the engine is turned off and cooled down.

2. 2

   Access the Sensor

   Locate the Exhaust Manifold Pressure Sensor / EGR Pressure Sensor on the engine (typically near the exhaust manifold or top of the valve cover).

3. 3

   Disconnect

   Unplug the electrical connector from the sensor. Inspect the pins for corrosion or bent terminals.

4. 4

   Remove Sensor

   Unbolt or unscrew the sensor from the exhaust manifold pressure line.

5. 5

   Inspect the Line

   Check the metal sensor line/tube (EGR pressure sensor line) that connects the manifold to the sensor. Ensure it is not plugged with soot or cracked. Clean or replace the line if necessary.

6. 6

   Install New Sensor

   Thread the new sensor into place and tighten to OEM specifications. Reconnect the electrical harness.

7. 7

   Clear Codes & Test

   Turn the key on, reset the ECU to clear the 001209.03 error code, and start the engine. Perform a manual regeneration (if applicable to your machine) to verify the sensor operates correctly and the code does not return.