Suzuki GRAND VITARA XL-7 Owner's Manual page 249

6-1-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Step
5 CMP sensor (REF) signal check :
1) With ignition switch OFF, connect CMP sensor
coupler.
2) Disconnect couplers from ignition coil assembly
and fuel injectors.
3) With ignition switch ON and crankshaft turned
slowly, check voltage between C51-1-13 and
C51-3-26 terminal.
Does voltmeter indicator deflect between 0 – 1 V
and 3 – 5.25 V 4 times while crankshaft turned two
revolutions?
6 CMP sensor (POS) signal check :
1) With ignition switch ON and crankshaft turned
slowly, check voltage between C51-1-12 and
C51-3-26 terminal.
Does voltmeter indicator deflect between 0 – 1 V
and 3 – 5.25 V 6 times while crankshaft turned two
revolutions?
Fig. for Step 4
Action
1. Disconnected CMP sensor coupler
2. "BLU/BLK" wire (C09-2) terminal
3. "GRY/YEL" wire (C09-1) terminal
Yes
Go to Step 6.
Poor C51-1-12 and/or
C51-3-13 terminal of
ECM (PCM) coupler con-
nection.
If OK, substitute a
known-good ECM (PCM)
and recheck.
No
Faulty "YEL/GRN" wire
or CMP sensor.
If OK, substitute a
known-good ECM
(PCM) and recheck.
Faulty "YEL/BLU" wire
or CMP sensor.
If OK, substitute a
known-good ECM
(PCM) and recheck.