Toyota CH-R Service Manual: Push Switch / Key Unlock Warning Switch Malfunction (B2780)

Toyota CH-R Service Manual / Theft Deterrent / Keyless Entry / Immobiliser System(w/o Smart Key System) / Push Switch / Key Unlock Warning Switch Malfunction (B2780)

DESCRIPTION

This DTC is stored if the transponder key ECU assembly does not detect that the unlock warning switch assembly is on even when the ignition switch is ON.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2780	Push Switch / Key Unlock Warning Switch Malfunction	The unlock warning switch assembly is not detected as being on when the ignition switch is ON (1 trip detection logic*).	Wire harness or connector Unlock warning switch assembly Transponder key ECU assembly	Insert the key into the ignition key cylinder.

*: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
Engine cannot be started	-

Related Data List and Active Test

DTC No.	Data List and Active Test
B2780	Key SW

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

If the transponder key ECU assembly is replaced, refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Immobiliser > Clear DTCs

2.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Immobiliser > Trouble Codes

HINT:

Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

OK:

DTC B2780 is not output.

Result	Proceed to
B2780 is not output	A
B2780 is output	B

USE SIMULATION METHOD TO CHECK

3.	INSPECT UNLOCK WARNING SWITCH ASSEMBLY

(a) Remove the unlock warning switch assembly.

Click here

(b) Inspect the unlock warning switch assembly.

Click here

REPLACE UNLOCK WARNING SWITCH ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (UNLOCK WARNING SWITCH ASSEMBLY - TRANSPONDER KEY ECU ASSEMBLY AND BODY GROUND)

(a) Disconnect the F13 unlock warning switch assembly connector.

(b) Disconnect the F22 transponder key ECU assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F13-1 (UN+) - F22-3 (KSW)	Always	Below 1 Ω
F13-2 (UN-) - Body ground	Always	Below 1 Ω
F13-1 (UN+) - Body ground	Always	10 kΩ or higher
F22-3 (KSW) - Body ground	Always	10 kΩ or higher

REPLACE TRANSPONDER KEY ECU ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

Unmatched Key Code (B2795)

DESCRIPTION This DTC is stored when a key with a different vehicle serial number is inserted into the ignition key cylinder. DTC No. Detection Item DTC Detection C ...

Antenna Coil Open / Short (B2784)

DESCRIPTION When an open or short circuit is detected in the antenna coil built into the transponder key coil, the transponder key ECU assembly stores this DTC. DTC No. Detec ...

Other materials:

Toyota CH-R Service Manual > Smart Key System(for Entry Function): Back Door Entry Lock and Unlock Functions do not Operate
DESCRIPTION If the entry lock and unlock functions do not operate for the back door only, the request code may not be being transmitted from the back door. If the entry functions for other doors operate properly, communication between the electrical key transmitter sub-assembly and electrical ...

Toyota CH-R Service Manual > Continuously Variable Transaxle Fluid: Adjustment
ADJUSTMENT PROCEDURE 1. PRECAUTIONS AND WORK DESCRIPTION (a) The K114 continuously variable transaxle assembly does not have an oil filler tube or oil level gauge. When adding fluid, add fluid through the refill hole in the continuously variable transaxle assembly. The fluid level can be adju ...

Toyota CH-R Service Manual: Push Switch / Key Unlock Warning Switch Malfunction (B2780)

Unmatched Key Code (B2795)

Antenna Coil Open / Short (B2784)

Other materials:

Toyota C-HR (AX20) 2023-2026 Owner's Manual

Toyota CH-R Owners Manual

Toyota CH-R Service Manual