John Deere 000158.01 – RLC / CLC: Switched Supply Voltage Low

The control unit has detected that the switched battery supply voltage (often referred to as ELX) is below a specified threshold. For example, the Cab Load Center (CLC) may detect voltage dropping below 12.5 volts for more than two seconds while the engine speed is above 1500 RPM. This is a general electrical system fault indicating low voltage on a switched power circuit, which can be logged by the CLC, Armrest Control Unit (ACU), Hitch Control Unit (HCU), or Rate Controller 2000.

• 7200R
• 7215R
• 7230R
• 7260R
• 7280R
• 7R 210
• 7R 230
• 7R 250
• 7R 270
• 7R 290
• 7R 310
• 7R 330
• 7R 350
• 8130
• 8230
• 8330
• 8430
• 8530
• 8235R
• 8260R
• 8285R
• 8310R
• 8310RT
• 8335R
• 8335RT
• 8360R
• 8360RT
• 8R 230
• 8R 250
• 8R 280
• 8R 310
• 8R 340
• 8R 370
• 8R 410
• 9230
• 9330
• 9430
• 9530
• 9630
• 9460R
• 9R 390
• 9R 440
• 9R 490
• 9R 540

1. 1

   Cycle the key switch off and on to see if the code returns

2. 2

   Assess electrical load by temporarily turning off non-essential lights and accessories to see if the code clears

3. 3

   Check if increasing engine RPM boosts alternator output and resolves the low voltage issue

4. 4

   Inspect the battery and charging system (ensure battery is at least 12.6 volts when off, terminals are clean and tight, and visually inspect the alternator and its connections)

5. 5

   Check the relevant fuses for the CLC and RLC in the load center, typically located behind the operator's seat

1. 1

   Verify the fault source

   Check the diagnostic trouble code information on the tractor's display to identify whether the Roof Lighting Control Unit (RLC) or the Cab Load Center (CLC) is logging the fault.

2. 2

   Perform Preliminary Checks

   Follow the diagnostic checks listed above.

3. 3

   Inspect wiring and connections

   Carefully examine the wiring harnesses leading to the identified control module (RLC or CLC). Look for any signs of damage, corrosion, or loose connections, paying close attention to ground wires.

4. 4

   Test voltage at the module

   Using a multimeter, test the voltage directly at the power supply connector of the affected module to confirm the voltage drop.

5. 5

   Isolate the cause and repair

   If the voltage is low at the module connector, the problem lies within the charging system, battery, or wiring harness. If the voltage is stable and correct at the module, the module itself may be faulty and require replacement.

6. 6

   Consult a Dealer

   Due to the complexity of the electrical systems in these tractors, if the preliminary checks do not resolve the issue, it is highly recommended to contact a John Deere dealer for advanced diagnostics. They have access to detailed wiring diagrams and service manuals.