Suzuki Grand Vitara JB416 / JB420 / JB419. Manual — part 98

1A-339 Engine General Information and Diagnosis: For Diesel Engine Model

Troubleshooting

The sensors connected to supply No.2 are:
• EGR valve position sensor.
• Sensor for accelerator pedal position (APP) sensor (sub).
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 ECM 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 “C10-1” wire of EGR valve connector and “C86-43” terminal of ECM connector
– Between “C10-3” wire of EGR valve connector and “C86-20” terminal of ECM connector
– Between “E68-1” wire of accelerator pedal position (APP) sensor connector and “E66-15” terminal of ECM

connector

– Between “E68-6” wire of accelerator pedal position (APP) sensor connector and “E66-21” terminal of ECM

connector
Repair if necessary.

2. Check the insulation against +12 V of the following connections:

– Between “C10-1” wire of EGR valve connector and “C86-43” terminal of ECM connector
– Between “C10-3” wire of EGR valve connector and “C86-20” terminal of ECM connector
– Between “C10-2” wire of EGR valve connector and “C85-15” terminal of ECM connector
– Between “E68-1” wire of accelerator pedal position (APP) sensor connector and “E66-15” terminal of ECM

connector

– Between “E68-6” wire of accelerator pedal position (APP) sensor connector and “E66-21” terminal of ECM

connector

– Between “E68-5” wire of accelerator pedal position (APP) sensor connector and “E66-27” terminal of ECM

connector
Repair if necessary.

3. Check the insulation between the following connections after disconnecting the sensors and ECM:

– “E68-1” and “E68-5” wires of accelerator pedal position (APP) sensor connector.
– “C10-1” and “C10-2” wires of the EGR valve position 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: For Diesel Engine Model 1A-340

DTC P0670: Glow Plug Control Circuit

S6JB0A1124128

NOTE

• Cylinder number is counted from flywheel side.
• Conditions for applying fault finding procedures to stored faults:

The fault is declared present after several attempts to start the engine, or perform output test “Pre/
post Heater Relay Control” on SUZUKI scan tool.

• It is difficult or even impossible to start the engine when cold.
• If the fault is present, the Injection warning light (gravity 1 warning light) is lit.
• Use service wire for all operations on the ECM connectors.

Wiring Diagram
For wiring circuit and connector number, refer to “A-5 Engine and A/C Control System Circuit Diagram (DSL) in
Section 9A”.

Troubleshooting

Check the glow plug control module connections.
Check the connections on all the glow plugs.
Repair if necessary.
Check the condition of the 80A fuse on the battery fuse box.
Check the resistance of the glow plugs:
Replace any plug whose resistance is not less than 2

Ω at 20 °C, 68 °F.

Check the following connections for continuity and make sure there is no interference resistance:
• Between cylinder 3 glow plug terminal and “C74-5” wire of the glow plug control module connector
• Between cylinder 1 glow plug terminal and “C74-8” wire of the glow plug control module connector
• Between cylinder 4 glow plug terminal and “C74-4” wire of the glow plug control module connector
• Between cylinder 2 glow plug terminal and “C74-6” wire of the glow plug control module connector
Check for the presence of +12 V on “C74-7” wire of the glow plug control module (by 80A fuse on battery fuse
box).
If the fault is still present.
Check the ECM connections.
Check continuity and make sure there is no interference resistance on the following connection:
• Between “C74-3” wire of glow plug control module connector and “C85-1” terminal of ECM connector
• Between “C74-1” wire of glow plug control module connector and “C85-17” terminal of ECM connector
If the fault is still present, replace the glow plug control module.

1A-341 Engine General Information and Diagnosis: For Diesel Engine Model

DTC P0685: Main Relay Control Circuit

S6JB0A1124129

NOTE

• Conditions for applying the fault finding procedure to stored faults:

Only deal with this fault if this fault is stored.

• The main relay located on fuse box No.2.
• If the fault is present, the Injection warning light (gravity 1 warning light) is lit.
• Use service wire for all operations on the ECM connectors.

Wiring Diagram
For wiring circuit and connector number, refer to “A-5 Engine and A/C Control System Circuit Diagram (DSL) in
Section 9A”.

Detecting Condition

Troubleshooting

DTC P0697: Sensor Reference Voltage 3 Circuit

S6JB0A1124130

CAUTION

!

This fault may appear if the wiring harness has been damaged.
Follow the procedure described in “Electrical Circuit Inspection Procedure in Section 00”.
This check enables the condition and the conformity of the engine wiring harness to be checked.

NOTE

• Conditions for applying the fault finding procedure to stored faults:

The fault is declared present following a road test or after attempting to start the engine several
times.

• If the fault is present:

– The EGR function is inhibited.
– Engine stops.
– The Red stop warning light (gravity 2 warning light) is lit.

• Use service wire for all operations on the ECM connectors.

Wiring Diagram
For wiring circuit and connector number, refer to “A-5 Engine and A/C Control System Circuit Diagram (DSL) in
Section 9A”.

Detecting Condition

Displaying on SUZUKI scan tool

Detecting condition

D1

Relay cut out too soon

D2

Relay cut out too late

• Check the ECM connections.

Repair if necessary.

• Check the condition of the battery terminals making sure they are correctly tightened.

Check the condition of the main relay and its mounting.
Repair if necessary.

Check the following connection for continuity and for the absence of interference resistance:
• Between “E33-8” wire of main relay mounting connector and “C86-14” terminal of ECM connector
Repair if necessary.
If the fault is still present, substitute a known-good ECM and recheck.

Displaying on SUZUKI scan tool

Detecting condition

D1

Sensor reference voltage too low

D2

Sensor reference voltage too high

Engine General Information and Diagnosis: For Diesel Engine Model 1A-342

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.