Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code F: Mode Control Motor
2004 Acura 3.5RLSECTION Code F: Mode Control Motor
- Disconnect mode control motor 5-pin harness connector. Test mode control motor. See MODE CONTROL MOTOR under COMPONENT TESTS. If mode control motor is okay, go to next step. If mode control motor is not okay, remove mode control motor. See MODE CONTROL MOTOR under REMOVAL & INSTALLATION. Check mode control motor linkage and doors for smooth operation. If doors and linkage operate smoothly, replace mode control motor. If doors and linkage do not operate smoothly, repair mode control motor doors and linkage.
- Disconnect 8-pin and 20-pin harness connectors and remove climate control unit. Individually check for continuity between ground and terminals No. 2 (Pink/Blue wire) and No. 3 (Gray wire) of climate control unit 8-pin harness connector. Individually check for continuity between ground and terminals No. 7 (Blue wire), No. 8 (Light Green/Red wire), and No. 14 (Light Green/Black wire) of climate control unit 20-pin harness connector. See Figure. If continuity does not exist, go to next step. If continuity exists, repair short in appropriate wire(s) between climate control unit and mode control motor.
- Individually check for voltage between ground and terminals No. 2 (Pink/Blue wire) and No. 3 (Gray wire) of climate control unit 8-pin harness connector. Individually check for voltage between ground and terminals No. 7 (Blue wire), No. 8 (Light Green/Red wire), and No. 14 (Light Green/Black wire) of climate control unit 20-pin harness connector. See Figure. If voltage does not exist, go to next step. If voltage exists, repair short to power in appropriate wire(s) between climate control unit and mode control motor. If short to power exists, climate control unit must be replaced.
- Check for continuity in Gray and Pink/Blue wires of climate control unit 8-pin harness connector and mode control motor 5-pin harness connector. Check for continuity in Blue, Light Green/Red and Light Green/Black wires between climate control unit 20-pin harness connector and mode control motor 5-pin harness connector. If continuity exists, go to next step. If continuity does not exist, repair open in wires between climate control unit and mode control motor.
- Check for loose wires or poor connections at climate control unit 8-pin and 20-pin harness connectors, and mode control motor 5-pin harness connector. If connections are okay, substitute known-good climate control unit and recheck. If symptom does not exist after substituting known-good climate control unit, replace original climate control unit. See CLIMATE CONTROL UNIT under REMOVAL & INSTALLATION.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.