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.
Diagnostic Trouble Code (DTC) Information
2004 Volvo V70 L5-2.4L VIN 64 B5244S6SECTION Diagnostic Trouble Code (DTC) Information
Diagnostic trouble code (DTC) information ECM-940C
Condition
The diagnostic trouble code (DTC) is stored (signal missing) if the engine control module (ECM) is unable to communicate with the brake control module (BCM) on the controller area network (CAN).
The diagnostic trouble code (DTC) is stored (faulty signal) if the brake control module (BCM) has detected a faulty signal from the brake pedal position sensor. The diagnostic trouble codes (DTCs) may also be stored in the brake control module (BCM).
The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.
Substitute value
- Cruise control is disengaged when the fault is active.
Possible source
Faulty signal
- Fault trace the brake control module (BCM)
- Damaged brake pedal position sensor
- Damaged brake control module (BCM).
Signal missing
- Fault in the CAN communication between the engine control module (ECM) and the brake control module (BCM).
Fault symptom[s]
- Cruise control does not function at all.
RENDER: 1.0x
NO RELATED
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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.