Corrado L4-1781cc 1.8L SOHC SC (1991)
- switch OFF ignition
- reconnect CO potentiometer (G 74) harness connector
- eliminate short in wiring between control unit and ground using wiring diagram
If wiring OK
- replace control unit (J 169)
- activate Fault memory and then erase
Test B
- disconnect CO potentiometer harness connector (with intake air temperature sensor) and bridge terminals 1 and 3 of connector using jumper wires
from VW 1594 adaptor kit
displayed value must be 0 to 2
If YES
-
control unit triggering OK
- switch OFF ignition.
- replace CO potentiometer (G 74) assembly
-
includes intake air temperature sensor (G 42)
- activate Fault memory and then erase
- check idle and CO values, adjust if necessary
-
displayed value must be 250 minimum
If NO
-
control unit triggering not OK
- switch OFF ignition
- reconnect CO potentiometer (G 74) harness connector
- determine open circuit and eliminate using wiring diagram
If wiring OK
- replace Digifant control unit (J 169)
- activate Fault memory and then erase