Diagnosis Procedure
- CHECK SELF DIAGNOSTIC RESULT
- Turn ignition switch ON.
- Check DTC using CONSULT.
What is the display history of DTC "B21F5-16"?
"PAST"
GO TO 2.
"CRNT"
GO TO 3.
- ERASE DTC
- Select "Self Diagnostic Result" mode of "BCM" using CONSULT.
- Erase DTC, and then repeat "DTC CONFIRMATION PROCEDURE". Refer to DTC Description .
Is DTC "B21F5-16" detected?
YES
GO TO 3.
NO
Check intermittent incident. Refer to Intermittent Incident .
- CHECK BATTERY VOLTAGE
- Turn ignition switch OFF.
- Check battery voltage is more than 9 V and less than 16 V.
Is the inspection result normal?
YES
GO TO 4.
NO
Perform battery inspection. Refer to Work Procedure .
- CHECK ALTERNATOR
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 5.
NO
Repair as needed.
- CHECK FUSE
Check that the following fuse and fusible link are not blown (open).
Signal name
Fuse No.
Ignition ON power supply
25 (30 A)
80 (40 A)
79 (40 A)
236 (40 A)
C (40 A)
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 6.
- CHECK BCM POWER SUPPLY CIRCUIT
- Disconnect following connectors
- BCM
- Fuse box
- Fuse and fusible link block 1
- Fuse and fusible link block 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
- 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
- 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
- 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 7.
NO
Repair or replace harness.
- Disconnect following connectors
- CHECK BCM GROUND CIRCUIT
Check continuity between BCM harness connector and ground.
BCM
--
Continuity
Connector
Terminal
M26
18
Ground
Existed
E14
118
Is the inspection result normal?
YES
Replace BCM. Refer to Removal and Installation .
NO
Repair or replace harness.