John Deere 1551.03 – ATC: Pressurizer Blower Motor Circuit Voltage High

The system has detected that the voltage in the A/C cab pressurizer blower motor circuit is too high, indicating a potential short to power, a faulty relay, or a failed blower motor.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7715
• 7815
• 7720
• 7820
• 7920
• 8130
• 8230
• 8330
• 8430
• 8530
• 8230T
• 8330T
• 8430T
• 8245R through 8400R
• 8310RT
• 8335RT
• 8360RT
• 9230
• 9330
• 9430
• 9530
• 9630
• 9470RT
• 9520RT
• 9570RT
• 8100
• 8200
• 8300
• 8400
• 8110
• 8210
• 8310
• 8410
• 9100-9630
• 4040-4840

1. 1

   Restart the tractor engine to verify if the active Service Code reappears, as it can be triggered by a temporary communication glitch.

2. 2

   Check the ATC relays and fuses (e.g., K2-AC Relay, Pressurizer Blower Motor and ATC power fuses). Ensure the battery is disconnected before inspecting master fuses.

3. 3

   Inspect the wiring harness running from the ATC module to the cab roof pressurizer blower motor for chafed wires causing a short to a power source.

4. 4

   Disconnect the pressurizer blower motor and test the circuit voltage. If the voltage returns to normal ranges with the motor unplugged, the motor itself has likely failed internally.

1. 1

   Disconnect Power

   Ensure both negative (-) and positive (+) battery connections are disconnected prior to servicing the electrical system or replacing components.

2. 2

   Access the Roof Module

   Remove the cab roof cover to access the Heater/Air Conditioning Compartment and the pressurizer blower motor assembly.

3. 3

   Replace Faulty Components

   If the wiring is damaged, repair or replace the affected harness section. If the K2-AC relay is stuck closed (sending constant high voltage), replace the relay. If the motor has failed, unbolt the pressurizer blower motor, disconnect the 2-wire pigtail, and install the replacement motor.

4. 4

   Reassemble and Clear Codes

   Reinstall the cab roof cover, reconnect the batteries, turn the key to the ON position, and use the CommandCenter to acknowledge and clear the stored ATC codes. Run the ClimaTrak system to verify the pressurizer fan operates without throwing the 001551.03 code.