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DTC B210A: +B power supply (low)
DTC B210B: +B power supply (high)
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)
 
 
TROUBLE JUDGMENT
The ETACS-ECU sets DTC No. B210A if the power supply fuse (IOD fuse) voltage decreases to the specified value or less, and sets DTC No. B210B if the power supply fuse (IOD fuse) voltage increases to the specified value or more. However, when the status returns to normal, the ETACS-ECU automatically erases DTC Nos. B210A and B210B.
 
 
TECHNICAL DESCRIPTION (COMMENT)
The power supply fuse or the ETACS-ECU may have a problem.
 
 
TROUBLESHOOTING HINTS
  • The power supply fuse may be defective.
  • The ETACS-ECU may be defective.
  • The battery may be defective.
  • The generator may be defective.
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Power supply fuse check.
Is the fuse in good condition?
Go to Step 2.
Replace the power supply fuse, and then go to Step 7.
 
STEP 2. Battery check.
Refer to GROUP 54A - Battery Test .
Is the battery in good condition?
Go to Step 3.
Charge or replace the battery.
 
STEP 3. Charging system check.
Refer to GROUP 16 - Charging System .
Is the charging system in good condition?
Go to Step 4.
Repair or replace the charging system component(s).
 
STEP 4. Voltage measurement at ETACS-ECU connector (IODI terminal).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the ETACS-ECU connector (IODI terminal) and ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 6.
Go to Step 5.
 
STEP 5. Check of short to power supply, short to ground, and open circuit in IODI line between fusible link and ETACS-ECU connector.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.
 
STEP 6. Using scan tool (M.U.T.-III), check data list.
Check the power supply fuse voltage.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan Tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Check the ETACS data list.
  • Turn the ignition switch to the "LOCK" (OFF) position.
 
Item No.Item nameNormal condition
253Voltage sensing of IOD LineBattery positive voltage
Item No.Item nameNormal condition
253Voltage sensing of IOD LineBattery positive voltage
OK: Normal condition is displayed.
Is the check result normal?
Go to Step 7.
Replace the ETACS-ECU.
 
STEP 7. Recheck for diagnostic trouble code.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
Is the DTC set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction (GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).