Fault-Tracing
Fault-tracing DEM-P188974
Information
Note! A mechanical fault in the AOC unit can be one possible cause of the trouble code being set. Therefore a first step should be to check the AOC unit for any damage or oil leaks. Listen also for noise from the clutch/back axle. Remedy as necessary.
Other information:
- Test driving Active on Demand Coupling, automatic transmission, TF-80SC AWD, AW50/51 AWD Test Driving Active On Demand Coupling, Automatic Transmission
- For replacement of the AOC unit see: Differential electronic module (DEM), replacement Service and Repair
Continue - Checking pressure and temperature sensor
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Checking pressure and temperature sensor
Checking pressure and temperature sensor
Checking pressure and temperature sensor
Note! Reading out of oil pressure can take place first after the diagnostic trouble code (DTC) has been deleted. Therefore frozen values should be printed and saved before deleting takes place.
1. Test of pressure sensor.
- Ignition on.
- Press the VCT2000 symbol.
Hint: Correct pressure shall be 0.00 +/- 0.08 MPa.
- Engine idling
- Press the VCT2000 symbol.
Hint: Correct pressure shall be 0.38 +/- 0.08 MPa.
1. Test of temperature sensor.
- Ignition on.
- Press the VCT2000 symbol.
Hint: Normal value for ambient temperature when the vehicle is cold and (+20 to +50 °C) when the vehicle is driven.
If wrong value is read out, then diagnostic trouble code shall be erased and the sensor changed. After changing sensor, repeat the test procedure again.
Note! There are two types of sensors, an 80 bar and a 40 bar. Differential electronic module (DEM) has hardware number 30759701, 30785483, 30759682, 30783198, 30735844, or 30783018, an 80 bar pressure sensor shall be installed. If Differential electronic module (DEM) has another hardware number than above, a 40 bar sensor shall be installed.
Hint: For reading out of hardware number, see VIDA/DIAGNOSTICS/NETWORK/DEM.
Other information
- Temperature / pressure sensor active on demand coupling (AOC), replacing Service and Repair
Has the fault been remedied?
Yes - DONE
No - No Fault Found
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No Fault Found - Checking the component and wiring
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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 - Information
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Checking the connectors and leads
- Ignition off
- Check the connector between the Differential Electronic Module (DEM) and the feed pump with respect to contact resistance and oxidation.
- Check the lead between the Differential Electronic Module (DEM) and the feed pump for damage.
- Engine idling.
Check the voltage by measuring with a voltmeter on the control module connector to the pump motor. Measure between #1 and #2.
Note! The voltage is a pulse width modulated signal which can vary considerably and is only measurable a short while.
Remedy as necessary.
Other information:
- For replacement of the AOC unit see: Differential electronic module (DEM), replacement Service and Repair
- Signal specification Signal Description, Differential Electronic Module (DEM)
- Oil pump active on demand coupling (AOC), replacing, TF-80SC AWD Oil Pump Active On Demand Coupling (AOC), Replacing
- Differential electronic module (DEM), replacement Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
Note! After the AOC unit has been repaired or replaced, a test drive is required to check that the fault has been remedied.
- Ignition off
- Reinstall the connectors, components etc.
- Ignition on
Switch on the pump motor and check that it starts and runs normally.
Hint: The motor should hum and vibrate slightly. Listen with a screwdriver or stethoscope against the ear.
Other information:
- Test driving Active on Demand Coupling, automatic transmission, TF-80SC AWD, AW50/51 AWD Test Driving Active On Demand Coupling, Automatic Transmission
- Test driving Active on Demand Coupling, manual transmission, M66 AWD Test Driving Active On Demand Coupling, Manual Transmission
Is the feed pump working?
Yes - Troubleshooting procedure complete
No - Fault-tracing information
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Checking the component and wiring
- Ignition off.
Check the connector for the Differential electronic module (DEM). Check for damage and loose connections.
Check that the cable harness is intact and not trapped or damaged.
Check that the oil pressure sensor (13) is correctly installed and that it does not have any external damage. Check that the oil pressure sensor oil ducts are intact and free of dirt.
Remedy as necessary.
Other information
- Checking wiring and terminals Checking Wiring and Terminals
- Temperature / pressure sensor active on demand coupling (AOC), replacing Service and Repair
Is the function OK?
Yes - Troubleshooting procedure complete
No - Checking the connectors and leads
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