Suzuki Ignis Service Manual page 3279

6-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Step
3 Check IAT sensor voltage.
1) Disconnect connector from IAT sensor with
ignition switch turned OFF.
2) Check for proper connection to IAT sensor
at "LT GRN/BLK" and "ORN" wire terminals.
3) If OK, then turn ON ignition switch, check
voltage between "LT GRN/BLK" wire termi-
nal of IAT sensor connector and vehicle
body ground. See Fig. 1.
Is voltage about 4 – 6 V?
4 Check ECM voltage.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Remove ECM from vehicle body and con-
nect connectors to ECM.
3) Check for proper connection of ECM con-
nector at "C63-17" terminal.
4) If OK, then turn ON ignition switch, check
voltage between "C63-17" terminal of ECM
connector and vehicle body ground.
Is voltage about 4 – 6 V?
5 Check wire circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Turn ON ignition switch.
3) Check voltage between "LT GRN/BLK" wire
terminal of IAT sensor connector and vehi-
cle body ground.
Is voltage about 0 V?
6 Check wire circuit.
1) Measure resistance between "C63-17" ter-
minal of ECM connector and "LT GRN/BLK"
wire terminal of IAT sensor connector with
ignition switch turned OFF.
Is resistance below 5 Ω?
7 Check ground circuit.
1) Connect connectors to ECM.
2) Check for proper connection of IAT sensor
connector at "ORN" wire terminal.
3) Measure resistance between "ORN" wire
terminal of IAT sensor connector and body
ground.
Is resistance below 5 Ω?
8 Check ground circuit.
1) Measure resistance between "C63-28" ter-
minal of ECM connector and body ground.
Is resistance below 5 Ω?
Action Yes
Go to Step 7.
"LT GRN/BLK" wire open
circuit.
If wire and connection are
OK, go to Step 5.
Go to Step 6.
Go to Step 7.
Go to Step 9.
"ORN" wire open circuit or
high resistance circuit.
Poor "C63-28" connec-
tion.
No
Go to Step 4.
Go to Step 5.
"LT GRN/BLK" wire
shorted to other circuits.
If wire are OK, substitute
a known-good ECM and
recheck.
"LT GRN/BLK" wire in
high resistance circuit.
Go to Step 8.
Faulty ECM ground cir-
cuit.
If circuit are OK, substi-
tute a known-good ECM
and recheck.