Code No. C2100:
Abnormal battery voltage (Too low)
caution
If there is any problem in the CAN bus lines, an incorrect diagnosis
code may be set. Prior to this diagnosis, always diagnose the CAN bus lines.
OPERATION
4WD-ECU detects a power supply voltage abnormal drop, and if any abnormality occurs, it interrupts
the system.
DIAGNOSIS CODE SET CONDITIONS
If the following conditions are met when the system is activated, 4WD-ECU gradually switches the
control from 4WD to 2WD, flashes the 4WD/LOCK indicators alternately, and sets the
diagnosis code No. C2100.
IG1 voltage: Less than 8 V
Voltage between the battery and ETACS-ECU: Less than 8 V
Engine speed: more than 1500 r/min
PROBABLE CAUSES
Current trouble
Damaged wiring harness and connectors
Short to earth or open circuit between the battery and 4WD-ECU
Past trouble
Intermittent wiring harness or connector failure
note
For diagnosis procedures, refer to "How to treat past trouble". (Refer
to GROUP 00, How to Treat Past Trouble .)
DIAGNOSIS PROCEDURE
STEP 1. Battery voltage check
Check the battery voltage.
Q.
Is the check result normal?
Go to Step 2.
Charge or replace the battery.
STEP 2. Voltage measurement at the ETACS-ECU connector
(1)Disconnect the C-309 ETACS-ECU connector.
(2)Measure the voltage between the C-309 harness side connector terminal No. 1 and
the body earth. OK: Battery voltage
Q.
Is the check result normal?
Go to Step 11.
Go to Step 3.
STEP 3. Wiring harness check
Check the wiring harness between the battery and the C-309 ETACS-ECU connector for damage
or other problem.
Q.
Is the wiring harness in good condition?
Go to Step 4.
Repair damage or other problem in the wiring harness. Then go to Step 11.
STEP 4. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 6.
Repair the CAN bus line. (Refer to GROUP 54C -
Troubleshooting .)
On completion, go to Step 5.
STEP 5. Check whether the diagnosis code is reset after repairing
the CAN bus line.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Start the engine, and continue to run at 1500 r/min or more.
(4)Check if the diagnosis code is set.
Q.
Is the diagnosis code No. C2100 set?
Go to Step 6.
This diagnosis is complete.
STEP 6. Check the following connector:
Check the connectors below for improper engagement, terminal damage or terminal drawn
in the connector case.
C-130 4WD-ECU connector
C-309, C-315 ETACS-ECU connector
C-35 intermediate connector
Q.
Are the connectors and terminals in good condition?
Go to Step 7.
Repair the connector(s) or terminal(s). Then go to Step 11.
STEP 7. Wiring harness check
Check the wiring harness between the C-130 4WD-ECU connector and the C-315 ETACS-ECU connector
for damage or other problem.
Q.
Is the wiring harness in good condition?
Go to Step 8.
Repair damage or other problem in the wiring harness. Then go to Step 11.
STEP 8. Voltage measurement at the 4WD-ECU connector
(1)Disconnect the C-130 4WD-ECU connector.
(2)Measure the voltage between the C-130 wiring harness side connector terminals No.
4 and No. 10. OK: Battery voltage
Q.
Is the check result normal?
Go to Step 9.
Go to Step 11.
STEP 9. Wiring harness check
Check the wiring harness between the C-130 4WD-ECU connector (terminal No. 3) and the
C-309 ETACS-ECU connector (terminal No. 1) for damage or other problem.
Q.
Is the wiring harness in good condition?
Go to Step 10.
Repair the wiring harness. Then go to Step 11.
STEP 10. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Start the engine, and continue to run at 1500 r/min or more.
(4)Check if the diagnosis code is set.
Q.
Is the diagnosis code No. C2100 set?
Replace 4WD-ECU. (Refer to .) Then go to Step
11.
The trouble can be an intermittent malfunction. (Refer to GROUP 00 -
How
to Cope with Intermittent Malfunction .)
STEP 11. Check whether the diagnosis code is reset.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Start the engine, and continue to run at 1500 r/min or more.