John Deere 108.07 – Engine Control Unit (ECU): Barometric Pressure Signal Mismatch

The internal barometric pressure reading does not logically align with other sensors (such as the Manifold Absolute Pressure sensor when the engine is off), indicating a mechanical system mismatch or a faulty signal from the internal barometric sensor.

• 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
• 5095M
• 5105M
• 8310RT
• 8335RT
• 8360RT
• 9470RT
• 9520RT
• 9570RT
• 7180
• 7280
• 7380
• 7480
• 7580
• 7780
• 7980
• 3029 Diesel Engine
• 6090 Diesel Engine

1. 1

   Perform a Sensor Comparison Test using Service ADVISOR to view live data for both the Barometric Pressure Sensor and the Manifold Air Pressure (MAP) sensor with the key ON and engine OFF (both should read identical ambient atmospheric pressure).

2. 2

   Inspect the ECU housing vent to ensure it is not packed with mud, dirt, or water, which blocks ambient air pressure from reaching the internal sensor.

3. 3

   Verify main power and ground pins at the ECU harness to rule out voltage drops or poor grounds causing the ECU's internal 5V reference to fluctuate.

4. 4

   Check if there is a software update available for the ECU to resolve overly sensitive logic parameters causing false flags in older software versions.

1. 1

   Clean the ECU

   Locate the Engine Control Unit on the machine. Carefully clean the exterior of the module, paying special attention to the atmospheric vent.

2. 2

   Clear and Retest

   Clear the fault code using a diagnostic tool. Cycle the key and see if the code returns immediately.

3. 3

   Update Software

   If the code returns and the vent is clear, connect Service ADVISOR and flash the ECU with the latest payload/calibration file from John Deere.

4. 4

   Replace the ECU

   If the wiring is good, the MAP sensor is reading correctly, the software is up to date, and the code persists, the internal barometric sensor has permanently failed. You must replace the entire Engine Control Unit.

5. 5

   Program the New ECU

   Install the replacement ECU and use Service ADVISOR to program the module with the machine's VIN, engine serial number, and injector trim codes.