Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: ENG / EHV Device (C1A40)

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Audio & Visual & Telematics / Park Assist / Monitoring / Intelligent Clearance Sonar System / ENG / EHV Device (C1A40)

DESCRIPTION

When an EFI system malfunction signal sent by the ECM is detected by the clearance warning ECU assembly, DTC C1A40 is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1A40

ENG / EHV Device

When the engine switch is on (IG), an EFI system malfunction signal is detected for 1 second or more.
  • EFI system
  • Clearance warning ECU assembly

CAUTION / NOTICE / HINT

NOTICE:

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

    Click here

  • After replacing an ultrasonic sensor or the clearance warning ECU assembly, perform the necessary procedures (adjustment, calibration, initialization or registration).

    Click here

PROCEDURE

1.

CHECK DTC OUTPUT

(a) Using the Techstream, check for DTCs according to the prompts on the screen.

Click here

HINT:

After turning the engine switch from off to on (IG), wait 4 seconds or more before checking for DTCs.

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

(b) Clear the DTCs according to the screen on the Techstream.

Click here

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(c) Recheck for DTCs.

Click here

Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

HINT:

  • DTC C1A40 is stored when a malfunction signal sent from the EFI system is detected.
  • If the malfunctioning part has been repaired or replaced before rechecking for DTCs, DTC C1A40 will not be output again.
  • If DTC C1A40 is output frequently, duplicate the conditions that cause the problem symptoms and perform the inspection again, even though the DTC was not output when rechecking for DTCs.

    Click here

Result

Proceed to

DTC C1A40 is output

A

DTC C1A40 is not output

B
A

GO TO EFI SYSTEM

B

USE SIMULATION METHOD TO CHECK

    Vehicle Information Unmatched (C168D)
    DESCRIPTION If the vehicle information stored in the main body ECU (multiplex network body ECU) which is sent via CAN communication during the clearance warning ECU assembly self-diagnosis does not ma ...

    Stop Light Relay Circuit (C1A4B)
    DESCRIPTION When a stop light relay circuit malfunction signal sent from the vehicle stability control system is detected by the clearance warning ECU assembly, DTC C1A4B is stored. DTC No. Detec ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Airbag System: Short in P Squib Circuit (B1805-B1808)
    DESCRIPTION The front passenger squib circuit consists of the airbag sensor assembly and instrument panel passenger airbag assembly. The airbag sensor assembly uses this circuit to deploy the airbag when deployment conditions are met. These DTCs are stored when a malfunction is detected in the front ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Sfi System: Throttle/Pedal Position Sensor/Switch "D" Circuit Short to Battery (P212012,P212014,P21201F,P212512,P212514,P21251F,P21382B)
    DESCRIPTION HINT: This Electronic Throttle Control System (ETCS) does not use a throttle cable. These DTCs relate to the accelerator pedal position sensor. The accelerator pedal position sensor is built into the accelerator pedal sensor assembly and has 2 sensor circuits: VPA (main) and VPA2 ...

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

    © 2026 Copyright www.lexusrx.net
    0.0151