Golf GTI L4-1781cc 1.8L SOHC (HT) (1985)
If terminals OK
-
connect ohmmeter across terminals of frequency valve
^
must read 2-3 Ohms
If ohm reading NOT OK
-
replace frequency valve and recheck
If ohm reading OK
-
check for voltage across terminals of frequency valve connector with test light
^
test light must go ON
If light goes ON
-
replace frequency valve and recheck
If light DOES NOT go on
-
check for open circuit in wiring between frequency valve connector, oxygen sensor relay and control unit (refer to current flow diagram)
If circuits OK
-
replace oxygen sensor relay
If light still DOES NOT go on
-
replace OXS control unit and recheck system
OXS control unit, checking
Cold enrichment
-
switch US 4480/3 ON