Case IH 12645 – ABS Control Module or Trailer Brake Control Module: Pneumatic output - delivery port exhaust solenoid electrical error

This fault indicates an electrical circuit malfunction (such as an open circuit, short to ground, or short to power) affecting the exhaust solenoid on a pneumatic modulator valve. The exhaust solenoid is responsible for opening and closing the air passage between the delivery port and the exhaust port to control air pressure to the brake chambers. An electrical error means the controller cannot properly communicate with or actuate this solenoid coil.

• Magnum
• Steiger
• Optum

1. 1

   Inspect the wiring harness and electrical connector at the pneumatic modulator valve assembly for corrosion, pushed-out pins, moisture intrusion, or chafed wires.

2. 2

   Disconnect the harness from the modulator valve and use a multimeter to measure the resistance across the exhaust solenoid pins to check for an internal short or open.

3. 3

   Check the wiring harness between the ECU and the modulator valve for continuity, verifying there is no short to ground or short to power.

4. 4

   Perform an active command test using a diagnostic service tool to command the exhaust solenoid on and off, verifying the ECU sends the correct voltage.

1. 1

2. 2

   Disconnect power

   Turn off the machine's ignition and disconnect the battery ground cable.

3. 3

   Deplete air pressure

   Safely drain the air from the pneumatic brake reservoirs to prevent injury when working on the pneumatic valves.

4. 4

   Repair wiring

   If diagnostic checks revealed a broken wire or corroded connector, splice in a new connector pigtail or repair the damaged wire section using weather-sealed heat shrink connectors.

5. 5

   Replace the valve

   If the exhaust solenoid coil failed the resistance test, replace the solenoid or the entire modulator valve assembly. Disconnect the electrical harness, mark and disconnect the pneumatic air lines from the supply, delivery, and exhaust ports, unbolt the modulator valve from its mounting bracket, install the new valve, reconnect the air lines to their respective ports, and plug in the electrical connector.

6. 6

   System test

   Reconnect the battery, start the tractor to build air pressure, and check for air leaks with soapy water. Clear the fault code using a diagnostic tool and perform a brake application test.