Faulty Signal

2004 Volvo S80 L6-2.9L Turbo VIN 91 B6294TSECTION Faulty Signal





Faulty signal

Fault-tracing information




Fault-tracing information

Caution! The male and female pins on the electronic throttle unit connectors are gold plated. Great care must be taken when measuring. Damage to the gold plating can result in operating difficulties.





Continue - Checking components and wiring

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Checking components and wiring




- Ignition off.
Check the throttle unit and engine control module (ECM) connectors. Check for contact resistance and oxidation.
Check the resistance values of the potentiometers in the throttle unit.
Check the signal cable (potentiometer 1) between engine control module (ECM) terminal #A1 (#A1) and throttle unit terminal #6 (wiring side). Check for an open-circuit.
Check the signal cable (potentiometer 2) between engine control module (ECM) terminal #A20 (#A20) and throttle unit terminal #5 (wiring side). Check for an open-circuit.
Check the signal cables (potentiometer 1) terminal #A1 (#A1) and (potentiometer 2) terminal #A20 (#A20). Check for a short-circuit to each other.

Hint: With the ignition on, the power supply to the throttle unit potentiometers must be approximately 5 V measured between throttle unit connector terminals #2 and #3 (wiring side).

If no faults are found during the checks and the diagnostic trouble code (DTC) recurs, try replacing the throttle unit.

Note! When replacing the throttle unit, the throttle unit must be adapted. See Throttle unit adaptation in the vehicle communication socket.

Remedy as necessary.

Other information:
- Checking wiring and terminals Checking Wiring And Terminals
- For resistance values, see Component specifications Specifications
- To connect the breakout box, see Connecting the breakout box, B5254T2 Connecting the Test Box
- 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
- To access or replace the throttle unit, see Throttle body (electronic throttle module (ETM)), replacing Removal and Replacement.













Continue - Verification

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Verification




Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off
- Reinstall the connectors, components etc.
- Start the engine
- Read off diagnostic trouble codes (DTCs).
The fault has been remedied if status of the diagnostic trouble code (DTC) is intermittent.





Is the status of the diagnostic trouble code (DTC) intermittent?

Yes - Verification completed

No - Fault-tracing information

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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

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Attempt New Test - Fault-tracing information

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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.