Honda Prelude 1993 Service Manual page 339

(From page 1 1-96)
Measure voltage between the
YEL/BLK wire 8nd body ground.
Rop6ir open in YEL/BLK wiro bo-
twoon ths IAC valvc.nd PGM-FI
main relay.
Turn the ignition switch ott and
reconnect the 2P connector to the
IAC valve.
Connect the test hamess "A"
connector to the main wire har-
ness only. not the ECM lsee page
1 1 - 4 5 ) .
Turn the ignition switch ON.
Mofientarily connect Ag terminal
to A26 terminsl several times.
Subrtitut
. known{ood ECM
.nd r.to.t. lt rymptom/ktdicrtkrn
gooa away, raplaca tho original
ECM.
Doos the IAC valve click?
Ropair opon or .hort in BLX/aLU
wirc b.tw.on IAC v.lvo and ECM
(A9l . It tho wlr. i! OK, r6pl.co th6
IAC valv6.