B2354

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

- The power supply circuit may be defective.
- The battery may be defective.
- The generator may be defective.
- The ETACS-ECU may be defective.
- The ignition switch 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
- 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) Reading and Clearing Diagnostic Trouble Codes."
(2)Check the ETACS data list.

- Turn the ignition switch to the "ON" position.





(3)Turn the ignition switch to the "LOCK" (OFF) position.

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

YES Go to Step 4.

NO Go to Step 2.

STEP 2. Battery check

Battery Test.

Q. Is the battery in good condition?

YES Go to Step 3.
NO Charge or replace the battery. Then go to Step 3.
STEP 3. Charging system check

Generator Output Line Voltage Drop Test.

Q. Is the charging system in good condition?

YES Inspection Procedure 2.
NO 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?

YES Replace the ETACS-ECU.
NO The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).