Code No.C1750: ACC/FCM-ECU Voltage out of Range

  • 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 GROUP 54A, Immobilizer System - How to Register Key ID .)


ACC/FCM-ECU power supply is provided from the battery via ETACS-ECU.


This diagnosis code is set when the abnormality below is detected:



STEP 1. Check the battery.

Refer to GROUP 54A - Battery Test .

Q. Is the check result normal?

Go to Step 2
Charge or replace the battery.

STEP 2. Check the charging system.

Refer to GROUP 16 - Charging System .

Q. Is the check result normal?

Go to Step 3
Repair or replace the charging system component(s).

STEP 3. Voltage measurement at ACC/FCM-ECU connector

(1)Check the connector
(2)Disconnect the connector.
(3)Turn the ignition switch to the "ON" position.
(4)Measure the voltage between terminal IG and body earth at the wiring harness side.
OK: System voltage

Q. Is the check result normal?

Go to Step 4
Repair the defective connector or the wiring harness (power supply line).

STEP 4. Check the wiring harness between ACC/FCM-ECU connector GND terminal line and body earth line .

Check the earth line for damage circuit.

Q. Is the check result normal?

Go to Step 5
Repair the defective the earth line.

STEP 5. M.U.T.-III data list.

Check the following data list (Refer to ).

  • Item No.01: ECU power supply voltage

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the ACC/FCM-ECU (Refer to ).