John Deere 636.05 – Engine Control Unit (ECU): Issue With Signal From Camshaft Position Sensor High Resistance

The Engine Control Unit (ECU) has detected high resistance in the electrical circuit of the camshaft position sensor, a condition also described as 'Cam Sensor Open'. The camshaft position sensor provides the ECU with precise timing information regarding the camshaft's rotational speed and position. High resistance disrupts this signal, which can negatively affect proper engine operation by disrupting fuel injection and ignition timing.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5065M
• 5075M
• 5085M
• 5100M
• 5100MH
• 5100ML
• 5115ML
• 5095M
• 5095MH
• 5105M
• 5015ML
• 5090M
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 9230
• 9330
• 9430
• 9530
• 9630
• 310J
• 135G
• 135P
• 190GW
• 230GW
• 245GLC
• 345GLC
• 3520
• 9560 STS
• 9650 STS
• 825i
• 590i
• 3029
• 4045
• 6068
• 10.5L
• 12.5L

1. 1

   Inspect the camshaft position sensor wiring harness and connectors for open circuits, intermittent connections, corrosion, or pushed-out pins.

2. 2

   Perform a sensor swap test: swap the camshaft and crankshaft position sensors (if they share the same part number). If the fault code changes to a crank sensor code (637.xx), the sensor is confirmed faulty. If it remains 636.05, the issue lies within the wiring harness or the ECU.

1. 1

   Disconnect battery

   Turn off the machine and disconnect the battery to prevent electrical shorts.

2. 2

   Locate sensor

   Locate the camshaft position sensor (also referred to as the Engine Position Sensor) on the engine block.

3. 3

   Disconnect connector

   Disconnect the electrical connector from the sensor.

4. 4

   Test wiring harness

   Using a multimeter, test the wiring harness between the sensor connector and the ECU to rule out an open circuit or short to ground. Repair any damaged wiring or connectors as necessary.

5. 5

   Remove mounting bolt

   If the wiring tests good (or if the sensor failed the swap test mentioned above), remove the mounting bolt securing the camshaft position sensor.

6. 6

   Replace sensor

   Remove the old sensor and install the new replacement part.

7. 7

   Secure and reconnect

   Secure the mounting bolt and reconnect the electrical harness.

8. 8

   Clear codes

   Reconnect the battery, turn the key to the ON position, and clear the stored ECU codes using a diagnostic tool or the onboard display.

9. 9

   Verify repair

   Start the engine to verify that cranking time has returned to normal and the 000636.05 code does not return.