Signal Missing. Permanent Fault

2004 Volvo S80 L6-2.9L Turbo VIN 91 B6294TSECTION Signal Missing. Permanent Fault





Signal missing. Permanent fault

Checking component and wiring
Check if there is any refrigerant in the air conditioning (A/C).

Hint: If there is refrigerant in the A/C system there is probably a fault in the A/C pressure sensor.

Check air conditioning (A/C) system for damage and leakage.
Remedy as necessary.

Other information:
- Connecting the breakout box/accessing the control module, see Connecting the breakout box, B5254T2 Connecting the Test Box.
- Air conditioning (A/C) pressure sensor #2 is the signal cable, #3 is the power supply (5V) and #1 is the signal ground.
- For resistance values, see Component specifications Specifications.
- 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

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Verification




Verification

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








- Ignition off.
- Reinstall connectors, components etc.
- Start the engine.
- Air conditioning (A/C) switch on
- Start the blower fan
Check that the pressure increases in the air conditioning (A/C) system when the air conditioning (A/C) compressor engages.
Also check if cold air blows into the passenger compartment when at the coolest setting.

Note! The air conditioning (A/C) pressure is given in volts for values see Component specifications Specifications.









Does the pressure in air conditioning (A/C) system change?

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 - Checking component and wiring

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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:

  • 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.