Suzuki Swift Sport 2004 Service & Repair Manual page 121

Step
3 Wire harness check
1) Disconnect MAF and IAT sensor connector (1) with
ignition switch turned OFF.
2) Check for proper connection to MAF and IAT sensor
connector (1) at "BLK/YEL" wire terminal.
3) If OK, then with ignition switch turned ON, measure
voltage between "BLK/YEL" wire terminal of MAF and
IAT sensor connector and vehicle body ground.
Is measured voltage applied to "BLK/YEL" wire terminal
about 4 – 6 V?
4 ECM voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its bracket with ECM connectors
connected.
3) Check for proper connection of ECM connector at "C37-
25" terminal.
4) If OK, then turn ON ignition switch, measure voltage
between "C37-25" terminal of ECM connector and
vehicle body ground.
Is voltage about 4 – 6 V at terminal?
5 Wire circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between "BLK/YEL" wire terminal of
MAF and IAT sensor connector and vehicle body
ground.
Is resistance infinity?
6 Wire circuit check
1) Turn ignition switch to ON position.
2) Measure voltage between "BLK/YEL" wire terminal of
MAF and IAT sensor connector and vehicle body
ground.
Is voltage about 0 V?
7 Wire circuit check
1) Measure resistance between "C37-25" terminal of ECM
connector and "BLK/YEL" wire terminal of MAF and IAT
sensor connector with ignition switch turned OFF.
Is resistance below 3
Action
Ω
?
Engine General Information and Diagnosis:
Yes
Go to Step 8.
I4RS0B110020-01
"BLK/YEL" wire is open
circuit.
If wire and connection
are OK, go to Step 5.
Go to Step 6.
Go to Step 7.
Go to Step 8.
1A-71
No
Go to Step 4.
Go to Step 5.
"BLK/YEL" wire is
shorted to ground or
other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
"BLK/YEL" wire shorted
to other circuit.
If wire is OK, substitute
a known-good ECM and
recheck.
"BLK/YEL" wire is high
resistance circuit.