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DTC B2353: Ignition power supply (low input)
DTC B2354: Ignition power supply (high input)


caution Before replacing the ECU, ensure that the input and output signal circuits are normal.




TROUBLE JUDGMENT


These DTCs are set when the ignition power supply voltage decreases to the specified value or less (DTC B2353) or increases to the specified value or more (DTC B2354). However, when the status returns to normal, the DTCs B2353 and B2354 are automatically erased.

TECHNICAL DESCRIPTION (COMMENT)


The power supply circuit or the ETACS-ECU may have a problem.

TROUBLESHOOTING HINTS



DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
  • MB991958 Scan Tool (M.U.T.-III Sub Assembly)

    • MB991824: Vehicle Communication Interface (V.C.I.)
    • MB991827 M.U.T.-III USB Cable
    • MB991910 M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, check data list.
Check the ignition power supply voltage.

(1)
caution To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2)Check the ETACS data list.

  • Turn the ignition switch to the "ON" position.
Item No.
 Item name
 Normal condition
Item 254
 IG voltage
 Approximately 12 volts (battery positive voltage)
(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Do the scan tool MB991958 display the item "IG voltage" is normal condition?

Go to Step 4.

Go to Step 2.

STEP 2. Battery check
Refer to .

Q. Is the battery in good condition?
Go to Step 3.
Charge or replace the battery.

STEP 3. Charging system check
Refer to GROUP 16 - Output Current Test .

Q. Is the charging system in good condition?
Refer to GROUP 54A, Diagnosis - Inspection Procedure 2 "ETACS-ECU does not receive any signal from the ignition switch (IG1)" .
Repair or replace the charging system component(s).

STEP 4. Recheck for diagnostic trouble .
Check again if the DTC is set to 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.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the DTC set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).