John Deere 000158.17 – FCC, RLC, CLC, or ECU: Module Supply Voltage Low

A control unit on the vehicle has detected a low voltage condition in its switched power supply. This indicates that the voltage being supplied to the controller when the key is on has dropped below the expected level. This condition can trigger an engine control unit power down error or affect other critical systems like the cab load center, transmission, or hydraulics.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7R Series
• 7630
• 7730
• 7830
• 7930
• 9230
• 9330
• 9430
• 9530
• 9630
• 5R Series
• 8R Series
• 9R Series
• S760
• 7200R
• 7210R
• 7215R
• 7230R
• 7M Series
• 6R 130

1. 1

   Test battery voltage with the engine off using a multimeter (a fully charged battery should read approximately 12.6 volts)

2. 2

   Test charging system voltage at the battery with the engine running at a moderate RPM (voltage should increase to between 13.5 and 14.5 volts)

3. 3

   Visually inspect battery terminals and ground connections for corrosion or looseness

4. 4

   Examine the wiring harnesses connected to the affected module for signs of wear, abrasion, or damage

5. 5

   Check for blown fuses in the circuits that supply power to the control modules

6. 6

   Reduce electrical load by turning off non-essential components (e.g., extra work lights) and restart the engine to check for temporary system overload

7. 7

   Cycle power by turning the ignition key off, waiting a few moments, and restarting the engine to see if a temporary glitch clears

1. 1

   Address battery and charging system

   If diagnostic checks reveal a weak battery (below 12.6V when off) or a malfunctioning alternator (fails to reach 13.5-14.5V when running), charge or replace the faulty components.

2. 2

   Repair wiring and connections

   Clean and tighten any loose or corroded battery terminals and ground connections. Repair or replace damaged wiring harnesses or connectors supplying power to the module.

3. 3

   Replace the faulty control module

   If power supply, charging, and wiring are all verified as good, the control module itself may be faulty and require replacement. Note that replacement modules may require dealer programming to function correctly.