John Deere 000158.18 – RLC, CLC, or FCC: Control Module Supply Voltage Below 11V

The switched supply voltage to a specific control module is below the normal operating range of 11 volts while the engine is running. Depending on the tractor series, this fault may be logged by the Roof Lighting Control Unit (RLC), Cab Load Center (CLC), or Front Console Control Unit (FCC). This low voltage condition can impair the proper operation of the affected module and the electrical components it controls.

• 6R Series
• 7R Series
• 8R Series
• 9x30 Series
• 9230
• 9330
• 9430
• 9530
• 9630
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7x30 Series
• 8x30 Series
• 6M Series

1. 1

   Assess the current electrical load, as a high number of active components can cause a voltage drop

2. 2

   Check engine RPM, as low engine speeds can result in reduced alternator output

3. 3

   Inspect battery and connections to ensure terminals and grounds are clean and tight

4. 4

   Verify the battery has a full charge of at least 12.6 volts using a multimeter

5. 5

   Examine fuses and wiring harnesses connected to the affected module for blown fuses or visible damage

1. 1

   Reduce load and increase RPM

   For RLC and FCC faults, reduce the electrical load by turning off non-essential lights and accessories. Increase the engine RPM to boost alternator output, then cycle the key switch off and on to see if the code clears.

2. 2

   Perform voltage drop test

   Use a multimeter to test for voltage drop across the power supply and ground circuits of the affected module to pinpoint high-resistance connections.

3. 3

   Test circuits and components

   Test individual circuits and components controlled by the RLC, CLC, or FCC for shorts or excessive current draw. Unplug accessories like floodlights to determine if they are the source of the issue.

4. 4

   Update module software

   If the issue persists, consult a dealer to check for incorrect software configuration. Recalibrate or update the control module software if necessary.

5. 5

   Replace control module

   If the module itself is determined to be faulty and cannot be repaired, replace it with the appropriate part for your machine series.