Starting System (Circuit Diagnosis)

WARNING: This page is about a different car, the 2020 Infiniti QX60. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Perform diagnosis under the condition that the engine cannot start by the following procedure.

Remove fuel pump fuse.
Crank or start the engine (where possible) until the fuel pressure is depleted.

CHECK TERMINAL B POWER SUPPLY VOLTAGE

Turn ignition switch OFF.
Make sure that starter motor connector F27 terminal B connection is clean and tight.

Check voltage between starter motor connector F27 terminal B and ground.

(+)

(-)

Voltage

(Approx.)

Connector

Terminal

F27

Ground

Battery voltage

Is the inspection result normal?

YES

GO TO 2.

Check harness between battery and starter motor for open circuit.

CHECK BATTERY CABLE (VOLTAGE DROP TEST)

Shift the transmission into P (Park) or N (Neutral).
Check voltage between battery positive terminal and starter motor connector F27 terminal B while cranking the engine.

(+)

(-)

Condition

Voltage

(Approx.)

Connector

Terminal

Battery (+) terminal

F27

While cranking the engine

Less than 0.5 V

Is the inspection result normal?

YES

GO TO 3.

Check harness between the battery and the starter motor for high resistance.

CHECK GROUND CIRCUIT STATUS (VOLTAGE DROP TEST)

Check voltage between starter motor case and battery negative terminal while cranking the engine.

(+)

(-)

Condition

Voltage

(Approx.)

Starter motor case

Battery (-) terminal

While cranking the engine

Less than 0.5 V

Is the inspection result normal?

YES

Terminal B circuit is OK. Further inspection is necessary. Refer to Work Flow (With 165-DSS-5000P) or Work Flow (Without 165-DSS-5000P) .

Check the starter motor case to engine mounting for high resistance.