Fault-Tracing Information

Fault-tracing

Checking the power supply and ground for the engine control module (ECM)

Checking the power supply
- Check the fuse for Engine control module (ECM) in the engine compartment fuse box. If the fuse is blown, check the circuit after the fuse. Check for a short-circuit to ground.
- Check the power supply to the engine control module (ECM). The voltage must be approximately battery voltage.

Checking the ground terminal
- Check the ground leads between the engine control module (ECM) and the ground terminal. Check for an open-circuit
- Check the control module ground terminal. Check for contact resistance and oxidation.
Remedy as necessary

Other information
- Checking wiring and terminals Checking Wiring and Terminals. Permanent Faults
- For further information about the circuit, see the relevant wiring diagram.

Was a fault detected?

Yes - Verification

No - Checking communication with the engine control module (ECM)

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Checking communication with the engine control module (ECM)
Try communicating with the engine control module (ECM) by selecting one of the functions under the DIAGNOSTICS tab. If, through this example, the ID number of the control module can be read off, communication is working with the control module at the moment.

Note! This stage is for obtaining an indication about how easy the fault is to find.

Continue - Signal missing

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Signal missing

DONE - DONE

No Fault Found - Fault-tracing information

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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.
- Switch on the ignition for at least 10 seconds.
Try communicating with the control module by selecting one of the functions for vehicle communication under the DIAGNOSTICS tab.

Is communication established?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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Fault-tracing information

Attempt New Test - Checking the power supply and ground for the engine control module (ECM)

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