Diagnostic

Wheel sensor extension is an important cable that connects the wheel sensors to ECU. Primary functions rely on this component, like ABS and Stability.

ECU have diagnostic capabilities to determine Diagnostic Trouble Codes (DTC) to help the technicians to find the root cause of the failure.

In case of an Open/Short circuit DTC, located on one of the wheel sensors (S1A, S1B, S2A or S2B) the wiring can be checked :

Test points

Condition

Required value

Measured value

Comments

ECU plug

1 - 2

Wheel sensor connected

980 Ω < R < 2400 Ω

Nominal = 1700 Ω

Additional test:

Turning wheels at 30 rpm must generate min 0,2 VAC voltage

This test will show the complete resistance of wiring AND sensor.

If value is out of this range, wheel sensor OR cable can be faulty!

Next steps :

check the values directly on sensor cable
check the continuity of the wires 1 and 2 with ohmmeter between the two plugs. (R<5Ω for correct operation)