Suzuki Grand Vitara 2011 Manual page 371

Troubleshooting for D1: Offset at minimum threshold
Check the fuel pressure sensor connectors.
Check the ECM connections.
Repair if necessary.
Check the following connections for continuity and make sure there is no interference resistance:
• 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
Repair if necessary.
With ignition switch ON and the engine stationary for more than one minute:
• Check for fuel pressure sensor output voltage between "C84-2" and "C84-1" wire of fuel pressure sensor
connector.
– If the voltage is above 0.5V, the sensor is in order.
• In this case, substitute a known-good ECM and recheck.
– If the voltage is below 0.5V, replace the fuel pressure sensor with common rail referring to "Common Rail
(High Pressure Fuel Injection Rail) Removal and Installation: For Diesel Engine Model in Section 1G".
Engine General Information and Diagnosis: For Diesel Engine Model 1A-302