check engine AUDI A4 1997 B5 / 1.G AFC Engine Idle Air Control Valve Checking Workshop Manual
Page 4 of 5
24-39
Checking Idle Air Control (IAC) valve
triggering
Idle Air Control (IAC) valve electrically OK
- Slide up boot on Idle Air Control (IAC) valve
connector.
- Use scan tool "Output Diagnostic Test Mode"
function 03 to trigger Idle Air Control (IAC) valve
-N71- Repair Group 01.
If specified results are not obtained: - Connect VAG 1527B voltage tester between connector terminal 1 and
engine Ground (GND).
Specified result: voltage tester must flash
- Connect voltage tester between connector terminal 2 and battery
positive voltage (B+).
Specified result: voltage tester must light up
- Connect VAG 1598/19 test box to ECM harness connector (ECM is left
disconnected) Repair Group 01.
Pa
ge 4 of 5 Idle Air Control
(IAC
) valve, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.8
Page 5 of 5
24-40
If the wiring is OK but triggering still does NOT occur:
If the triggering signal and the wiring are OK and the valve still does not
react: - Check wiring between harness connector terminal 1 (in engine
compartment) to test box socket D11, then check wiring between
harness connector terminal 2 and test box socket D9 using wiring
diagram; correct as necessary.
- Replace ECM Repair Group 01.- Replace Idle Air Control (IAC) valve.
Pa
ge 5 of 5 Idle Air Control
(IAC
) valve, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.8