Signal Too Low - Permanent Fault

Signal too low. Permanent fault

Checking component and wiring
Check air conditioning (A/C) pressure sensor connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check signal cable between engine control module (ECM) #A68 (#B8) and air conditioning (A/C) pressure sensor #2 for an short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check signal cable between engine control module (ECM) #A68 (#B8) and air conditioning (A/C) pressure sensor #2 for an open circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check power supply cable between engine control module (ECM) #A39 (#A39) and air conditioning (A/C) pressure sensor #3 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.

Other information:
- Connecting the breakout box/accessing the control module, see Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box.
- Air conditioning (A/C) pressure sensor #2 is the signal cable, #3 is the power supply (5 V) and #1 is the signal ground.
- For information about signals, see Signal specification Signal Specification, ECM.














Continue - Verification

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Verification




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 - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - Fault Found

VERIFICATION FAILED - Fault-tracing information

PAPER - No Fault Found

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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 - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking component and wiring

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