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.
System overview: Signals
The chart below summarizes input and output signals to and from the climate control module. The signal types are divided into directly connected signals, serial communication and Controller area network (CAN) communication. The illustration below displays the same information with the Volvo component designations.
| Input signals | Output signals |
| Directly connected: Sun sensor (7/12), (ECC) |
Directly connected: Blower fan motor (6/28), control signal |
| Blower fan motor (6/28), diagnostic signal | Damper motors for electronic climate control (6/48, 6/95-96, 6/102-103), control signal |
| Evaporator temperature sensor (7/41), control signal | Damper motors for manual climate control (6/48, 6/69, 6/95-96), control signal |
| Air quality sensor (7/159), (ECC, option) | Sun sensor (7/12), (ECC) |
| Via Controller Area Network (CAN): | Via Controller Area Network (CAN): |
| The central electronic module (CEM) (4/56) | The central electronic module (CEM) (4/56) |
| The engine control module (ECM) (4/46) | Driver's door module (DDM) (3/126) |
| Rear electronic module (4/58) | Passenger door module (3/127) |
| Brake control module (ABS-control module) (4/16) | Brake control module (ABS-control module) (4/16) |
| Driver's door module (DDM) (3/126) | Rear electronic module (4/58) |
| Passenger door module (3/127) | The engine control module (ECM) (4/46) |
| Upper electronic module (4/70) | |
| Steering wheel module (3/130) |
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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.
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