John Deere 522343.03 – RLC: Heated Rear Window, Voltage Too High

This diagnostic trouble code (DTC) is generated if a voltage higher than 16 volts is registered at the output pin to the heated rear window. This indicates that the circuit is shorted to a supply lead (short to power). The control software will limit or completely disable the function of the heated rear window to protect the circuit.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6155RH
• 770G
• 770GP
• 772G
• 772GP

1. 1

   Measure the voltage at the rear window heater output pin on the RLC module while the system is active to confirm if it is reading above 16V.

2. 2

   Disconnect the harness from the RLC and the rear window heater element, then test the power supply wire for continuity to other power leads or the battery to check for a short to power.

3. 3

   Inspect the defrost relay and its socket (if equipped) for fused or stuck contacts that could backfeed voltage.

4. 4

   Disconnect the rear window heater circuit entirely. If the code changes to 522343.05 (Current Too Low / Open Circuit), the RLC is functioning correctly and the short is in the wiring harness. If the high voltage code persists, the RLC module has an internal short.

1. 1

   De-energize the System

   Turn off the ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the RLC / Relay Panel

   Remove the interior cab roof headliner panels to access the Roof Lighting Control (RLC) module and associated harness connectors.

3. 3

   Repair the Wiring Harness

   If your diagnostic checks revealed a short to a supply lead in the harness, locate the chafed section (commonly found where wires route through the cab frame or near the window hinges). Splice and heat-shrink the damaged wire, or replace the harness section.

4. 4

   Replace the Relay (If Applicable)

   If the defrost relay is internally shorted, pull the old relay from the block, inspect the spade terminals for melting or thermal damage, and install a new relay.

5. 5

   Replace the RLC Module (If Internal Failure)

   If the module itself is outputting the high voltage due to an internal board failure, unbolt the RLC, disconnect the CAN and power connectors, and install the replacement module. (Note: A new RLC may require configuration/calibration to the tractor's CAN bus via John Deere Service ADVISOR).

6. 6

   Reassemble and Clear Codes

   Reconnect the battery, turn the key to the ON position, and use the CommandCenter display or Service ADVISOR to clear the stored 522343.03 code. Test the rear window heater to ensure the voltage remains in spec and the code does not return.