Suzuki GRAND VITARA 2005 Service Manual page 111

Troubleshooting
The sensors connected to supply No.3 are:
• Fuel pressure sensor.
• MAF sensor assembly with IAT sensor.
To locate any faulty sensor and/or connection, disconnect one of the sensors then check whether the fault
becomes stored.
If the fault is still present, repeat the operation with the other sensors.
(Wait a few seconds between each disconnection to allow the computer to make the measurement).
If the fault is stored after a disconnection, change the faulty sensor or repair its connection.
Clear the faults created by the multiple disconnections.
If the fault is still present when both these sensors have been disconnected:
1. Check the insulation against vehicle body ground of the following connections:
– Between "C84-2" wire of fuel pressure sensor connector and "C86-32" terminal of ECM connector
– Between "C84-3" wire of fuel pressure sensor connector and "C86-48" terminal of ECM connector
– Between "C13-6" wire of MAF sensor assembly with IAT sensor connector and "C86-12" terminal of ECM
connector
– Between "C13-5" wire of MAF sensor assembly with IAT sensor connector and "C86-47" terminal of ECM
connector
– Between "C13-2" wire of MAF sensor assembly with IAT sensor connector and "C86-24" terminal of ECM
connector
Repair if necessary.
2. Check the insulation against +12 V of the following connections:
– Between "C84-2" wire of fuel pressure sensor connector and "C86-32" terminal of ECM connector
– Between "C84-3" wire of fuel pressure sensor connector and "C86-48" terminal of ECM connector
– Between "C84-1" wire of fuel pressure sensor connector and "C86-46" terminal of ECM connector
– Between "C13-6" wire of MAF sensor assembly with IAT sensor connector and "C86-12" terminal of ECM
connector
– Between "C13-5" wire of MAF sensor assembly with IAT sensor connector and "C86-47" terminal of ECM
connector
– Between "C13-2" wire of MAF sensor assembly with IAT sensor connector and "C86-24" terminal of ECM
connector
3. Check the insulation between the following connections after disconnecting the sensors and ECM:
– Between "C84-1" and "C84-3" wires of fuel pressure sensor connector and "C13-2" and "C13-5" wires of
MAF sensor assembly with IAT sensor connector
If these checks do not produce the correct results, replace the faulty sensor(s).
If the fault is still present, substitute a known-good ECM and recheck.
Engine General Information and Diagnosis: 1A-79