Code 45 - THERMACTOR Air Diverter
- Remove vacuum hose from TAD valve and connect vacuum gauge to hose. Start engine and raise speed to 2500 RPM to begin "Functional Test". Observe gauge during initial pulses. If pulses are above and below 5 in. Hg, MCU is okay, check Thermactor pump. If pulses are always above 5 in. Hg, check Thermactor pump. If pulses are always below 5 in., Hg, go to next step.
- Check vacuum hoses between vacuum source, TAD solenoid, and TAD valve. If vacuum source or hoses are faulty, repair. If okay, go to next step.
- Measure resistance of TAD solenoid. If within 50-110 ohms, go to next step. If not, replace TAD solenoid.
- Check at TAD solenoid output for vacuum when solenoid is energized (12 volts). If no vacuum, replace solenoid. If vacuum is present, go to next step.
- Disconnect MCU connector and TAD connector. Measure resistance between MCU pin 10 and TAD connector, then between pin 20 and TAD connector. If resistance is less than 5 ohms, replace MCU module. If resistance is greater than 5 ohms, repair circuit.
- Check at TAD solenoid output to ensure vacuum is not present when solenoid is deactivated. If vacuum is present, replace solenoid. If no vacuum, go to next step.
- Measure resistance between MCU pin 10 and ground. If resistance is less than 1000 ohms, repair short circuit to ground. If resistance is more than 1000 ohms, replace MCU module.