Diagnosis Procedure

1. Turn ignition switch ON.
2. Check DTC using CONSULT.

What is the display history of DTC "B21F5-16"?

"PAST" 

GO TO STEP 2  .

"CRNT" 

GO TO STEP 3  .

1. Select "Self Diagnostic Result" mode of "BCM" using CONSULT.
2. Erase DTC, and then repeat "DTC CONFIRMATION PROCEDURE". Refer to DTC DESCRIPTION .

Is DTC "B21F5-16" detected?

YES 

GO TO STEP 3  .

NO 

Check intermittent incident. Refer to INTERMITTENT INCIDENT .

1. Turn ignition switch OFF.
2. Check battery voltage is more than 9 V and less than 16 V.

Is the inspection result normal?

YES 

GO TO STEP 4. 

NO 

Perform battery inspection. Refer to WORK PROCEDURE .

Perform alternator diagnosis and repair work flow. Refer to WORK FLOW (WITH EXP-800 NI OR GR8-1200 NI) or WORK FLOW (WITHOUT EXP-800 NI OR GR8-1200 NI) .

Is the inspection result normal?

YES 

GO TO STEP 5. 

NO 

Repair as needed.

Check that the following fuse and fusible link are not blown (open).

Is the fuse or fusible link blown (open)?

YES 

Replace the blown (open) fuse or fusible link after repairing the affected circuit if a fuse or fusible link is blown.

NO 

GO TO STEP 6. 

1. Disconnect following connectors
   • BCM
   • Fuse box
   • Fuse and fusible link block 1
   • Fuse and fusible link block 2
2. Check continuity between BCM harness connector and fuse box harness connector.

   BCM		Fuse box		Continuity
   Connector	Terminal	Connector	Terminal
   E14	117	E73	2	Existed

3. Check continuity between BCM harness connector and fuse and fusible link block 1 harness connector.

   BCM		Fuse and fusible link block 1		Continuity
   Connector	Terminal	Connector	Terminal
   E14	115	E62	27	Existed

4. Check continuity between BCM harness connector and fuse and fusible link block 2 harness connector.

   BCM		Fuse and fusible link block 2		Continuity
   Connector	Terminal	Connector	Terminal
   M26	15	M115	42	Existed
   	16	M125	52
   	17	M124	51

5. Check continuity between BCM harness connector and ground.

   BCM		-	Continuity
   Connector	Terminal
   E14	117	Ground	Not existed
   	115
   M26	15
   	16
   	17

Is the inspection result normal?

YES 

GO TO STEP 7. 

NO 

Repair or replace harness.

Check continuity between BCM harness connector and ground.

Is the inspection result normal?

YES 

Replace BCM. Refer to REMOVAL AND INSTALLATION .

NO 

Repair or replace harness.