SIGNAL NOT VALID (high resistance)
Test results
1
ELECTRICAL CONNECTIONS CHECK
All OK
Problems encountered
Operation
Check for loose electrical connections at the sensor connector and at the engine management control unit.
Go to Step 2
Presence of loose electrical connections.
Restore the correct connections.
2
WIRING CONTINUITY CHECK
Check for breaks in the wiring continuity caused by oxidised or corroded terminals.
Go to Step 3
Breaks in the wiring continuity.
Restore the correct continuity for the wiring.
3
WIRING INSULATION CHECK
Check the condition of the wiring insulation (short circuit between conductors).
Go to Step 4
Wiring insulation faulty.
Restore correct wiring insulation.
4
LAMBDA SENSOR OPERATION CHECK
Check that the Lambda sensor is working properly by performing the
See Test 1080BD Check on the operation of the downstream Lambda sensor
Go to Step 5
Lambda sensor not working properly.
Replace the Lambda sensor
Op. 1080B95 REAR LAMBDA SENSOR TO CATALYTIC CONVERTER - R.R
5
ENGINE MANAGEMENT CONTROL UNIT OPERATION CHECK
Check that the engine management control unit is working properly.
End of diagnosis
Engine management control unit faulty.
Replace the engine management control unit
Op. 1056B82 INJECTION/IGNITION SYSTEM E.C.U. (ONE) - R + R