Operation CHARM: Car repair manuals for everyone.
Home >> Nissan-Datsun Truck >> 2012 >> Pathfinder 2WD V8-5.6L (VK56DE) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> Power Supply And Ground Circuit

Power Supply And Ground Circuit




POWER SUPPLY AND GROUND CIRCUIT

Diagnosis Procedure


1. INSPECTION START

Start engine.
Is engine running?
Yes or No
Yes- GO TO 7.
No- GO TO 2.

2. CHECK ECM POWER SUPPLY CIRCUIT-I

1.Turn ignition switch OFF and then ON.





2.Check voltage between ECM terminal 109 and ground with
CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 4.
NG- GO TO 3.

3. DETECT MALFUNCTIONING PART

Check the following.
- Harness connectors E152, M31
- Fuse block harness connector M4
- 10A fuse (No. 1)
- Harness for open or short between ECM and fuse block
- Repair harness or connectors.

4. CHECK GROUND CONNECTIONS

1.Turn ignition switch OFF.
2.Loosen and retighten ground screws on the body.
.





OK or NG
OK- GO TO 5.
NG- Repair or replace ground connections.

5. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I

1.Disconnect ECM harness connector.
2.Check harness continuity between ECM terminals 115, 116 and ground.
Refer to Wiring Diagram.
Continuity should exist.
3.Also check harness for short to power.
OK or NG
OK- GO TO 6.
NG- Repair open circuit or short to power in harness or connectors.

6. CHECK ECM POWER SUPPLY CIRCUIT-II

1.Reconnect ECM harness connector.
2.Turn ignition switch ON.





3.Check voltage between IPDM E/R terminal 3 and ground with
CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- Go to Ignition Signal.
NG- GO TO 7.

7. CHECK ECM POWER SUPPLY CIRCUIT-III

1.Turn ignition switch OFF and wait at least 10 seconds.
2.Turn ignition switch ON and then OFF.





3.Check voltage between ECM terminals 119, 120 and ground with CONSULT or tester.

Voltage : After turning ignition switch OFF, battery voltage will exist for a few seconds, then drop to approximately 0 V.

OK or NG
OK- GO TO 12.
NG (Battery voltage does not exist.)-GO TO 8.
NG (Battery voltage exists for more than a few seconds.)-GO TO
10.

8. CHECK ECM POWER SUPPLY CIRCUIT-IV

1.Turn ignition switch OFF and wait at least 10 seconds.





2.Check voltage between ECM terminal 111 and ground with
CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 9.
NG- GO TO 10.

9. CHECK ECM POWER SUPPLY CIRCUIT-V

1.Disconnect ECM harness connector.
2.Disconnect IPDM E/R harness connector E119.
3.Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 4.
Refer to Wiring Diagram.
Continuity should exist.
4.Also check harness for short to ground and short to power.
OK or NG
OK- GO TO 12.
NG- Repair open circuit or short to ground or short to power in harness or connectors.

10. CHECK ECM POWER SUPPLY CIRCUIT-VI

1.Disconnect ECM harness connector.
2.Disconnect IPDM E/R harness connector E119.
3.Check harness continuity between ECM terminal 111 and IPDM E/R terminal 7.
Refer to Wiring Diagram.
Continuity should exist.
4.Also check harness for short to ground and short to power.
OK or NG
OK- GO TO 11.
NG- Repair open circuit or short to ground or short to power in harness or connectors.

11. CHECK FUSE

Check 20 A fuse (No. 53).
OK or NG
OK- GO TO 14.
NG- Replace 20 A fuse.

12. CHECK GROUND CONNECTIONS

1.Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
.





OK or NG
OK- GO TO 13.
NG- Repair or replace ground connections.

13. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II

1.Disconnect ECM harness connector.
2.Check harness continuity between ECM terminals 115, 116 and ground.
Refer to Wiring Diagram.
Continuity should exist.
3.Also check harness for short to power.
OK or NG
OK- GO TO 14.
NG- Repair open circuit or short to power in harness or connectors.

14. CHECK INTERMITTENT INCIDENT

Intermittent Incident.
OK or NG
OK- Replace IPDM E/R.
NG- Repair open circuit or short to power in harness or connectors.


Ground Inspection

Ground connections are very important to the proper operation of electrical and electronic circuits. Ground connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drastically affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
- Remove the ground bolt or screw.
- Inspect all mating surfaces for tarnish, dirt, rust, etc.
- Clean as required to assure good contact.
- Reinstall bolt or screw securely.
- Inspect for "add-on" accessories which may be interfering with the ground circuit.
- If several wires are crimped into one ground eyelet terminal, check for proper crimps. Check that all of the wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one eyelet, check that no ground wires have excess wire insulation.
For detailed ground distribution information, refer to "GROUND INSPECTION" in Circuit Inspection.




pro multis · About Operation CHARM