BCM Power Supply and Ground Circuit Check

WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FUSES AND FUSIBLE LINK
- Check 50A fusible link (letter f, located in the fuse and fusible link box).
- Check 10A fuses [No. 1, 6 and 21, located in the fuse block (J/B)].
OK or NG

OK: GO TO 2.

NG: If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse.

CHECK BCM POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect BCM.
Check voltage between BCM connectors and ground.

BCM POWER SUPPLY CIRCUIT

Connector	Terminals		Power source	Condition	Voltage (V) (Approx.)
Connector	(+)	(-)	Power source	Condition	Voltage (V) (Approx.)
M18	11	Ground	ACC power supply	Ignition switch ACC or ON	Battery voltage
M18	38	Ground	Ignition power supply	Ignition switch ON or START	Battery voltage
M20	57	Ground	Battery power supply	Ignition switch OFF	Battery voltage
M20	70	Ground	Battery power supply	Ignition switch OFF	Battery voltage

Fig 1: Checking Voltage Between BCM Connectors And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 3.

NG: Repair or replace the harness.

CHECK GROUND CIRCUIT
Check continuity between BCM connector M20 terminal 67 and ground.

67 - Ground: Continuity should exist.

Fig 2: Checking Continuity Between BCM Connector M20 Terminal 67 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: Power supply and ground circuit is OK.

NG: Repair or replace harness.