John Deere 101.04 – Engine Control Unit (ECU): Crank Case Pressure Signal Is Low

The Engine Control Unit (ECU) has detected that the crankcase pressure signal is below the expected range, signifying a low voltage signal from the sensor. This indicates an issue with the component responsible for monitoring crankcase pressure, often suggesting a potential short to ground in the sensor's wiring circuit, a faulty sensor, or a problem with the crankcase ventilation system.

• 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
• 6230R
• 6250R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 7200R
• 7215R
• 7230R
• 8345R
• 9470RT
• 9520RT
• 9570RT
• 9620RX
• 310K/L backhoes
• 450K-850K dozers
• 130G-300GLC excavators

1. 1

   Visually inspect the crankcase pressure sensor for signs of impact damage or physical breakage.

2. 2

   Inspect the wiring harness leading to the crankcase pressure sensor for chafed wires, melted insulation, or pinched lines that could cause a short to ground.

3. 3

   Disconnect the sensor and inspect the connector pins for corrosion, moisture, or pushed-out terminals. Verify that the sensor supply connection is not open.

4. 4

   Using a multimeter, test the signal circuit for a short to ground or an open circuit. If the wiring tests good, the internal circuitry of the sensor itself has likely failed.

1. 1

   Preparation

   Turn off the engine, remove the key, and allow the engine to cool. Locate the crankcase pressure sensor on the engine block.

2. 2

   Clean the Area

   Thoroughly clean the area around the sensor base to prevent dirt and debris from falling into the crankcase when the sensor is removed.

3. 3

   Removal

   Unplug the electrical connector from the sensor. Remove the mounting bolt(s) securing the sensor. Carefully extract the broken or faulty sensor.

4. 4

   Installation

   Insert the new crankcase pressure sensor into the port. Install and tighten a new mounting bolt (if required or if the old one is damaged) to the OEM torque specification.

5. 5

   Reconnection

   Plug the electrical connector back into the new sensor, ensuring it clicks securely into place.

6. 6

   Testing

   Turn the key to the ON position and clear the stored fault codes using a diagnostic scan tool. Start the engine and verify that code 000101.04 does not return and that the crankcase pressure readings are within normal parameters. If the code persists, the wiring harness must be repaired or replaced to resolve the short to ground.