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.
SYS.OK|MANUAL.DBβ LIVE
HOMESERVICE MANUALSVOLVO2004S80 L6-2.9L TURBO VIN 91 B6294TREPAIR AND DIAGNOSISA L L DIAGNOSTIC TROUBLE CODES ( DTC )TESTING AND INSPECTIONMANUFACTURER CODE CHARTSECM CODES (ENGINE CONTROL MODULE)ECM-720AFAULTY SIGNAL. PERMANENT FAULT
2004 Volvo S80 L6-2.9L Turbo VIN 91 B6294T
Faulty Signal. Permanent Fault
2004 Volvo S80 L6-2.9L Turbo VIN 91 B6294TSECTION Faulty Signal. Permanent Fault
Faulty signal. Permanent fault
Information
This diagnostic trouble code (DTC) indicates that the immobilizer code does not match between the engine control module (ECM) and the central electronic module (CEM). This may be because:
- the immobilizer code in the engine control module (ECM) is incorrect i.e. the code does not correspond to the code stored in the central electronic module (CEM)
- the engine control module (ECM) is not programmed and has no immobilizer code
- the immobilizer code in the central electronic module (CEM) is incorrect
- the central electronic module (CEM) is not programmed and has no immobilizer code
- the engine control module (ECM) is damaged
- the central electronic module (CEM) is damaged.
Note! A programmed engine control module (ECM) or central electronic module (CEM) cannot be moved from one vehicle to another.
Hint: Read off the diagnostic trouble codes (DTCs) for the central electronic module (CEM).
For further information about this diagnostic trouble code (DTC), select Information, then DTC information.
Other information:
- To access and replace the engine control module (ECM), see Engine control module (ECM), replacing Service and Repair
- To access or replace the central electronic module (CEM), see Central electronic module (CEM), replacing
- For information about signals on 5-cylinder engines, see Signal specification Signal Specification
- For information about signals on 6-cylinder engines, see Signal specification Signal Specification.
Continue - Verification
-------------------------------------------------
Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit Fault-Tracing
No - Attempt New Test
------------------------
Attempt New Test - Information
-------------------------------------------------
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall connectors, components etc.
- Start the engine.
Did the engine start?
Yes - FAULT FOUND
No - Fault-tracing information
-------------------------------------------------
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:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.