THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): B2271; Ignition Hold Monitor Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001H8D8
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): B2271; Ignition Hold Monitor Malfunction; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

B2271

Ignition Hold Monitor Malfunction

DESCRIPTION

This DTC is stored when a malfunction in the IG drive circuit or IG hold circuit of the certification ECU (smart key ECU assembly) or a malfunction in the IG output circuit between the output terminal of the certification ECU (smart key ECU assembly) and IG relay is detected.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2271	Ignition Hold Monitor Malfunction	When either of the following conditions is met (1-trip detection logic1): The IG circuit of the certification ECU (smart key ECU assembly) is malfunctioning.2 The IG hold circuit of the certification ECU (smart key ECU assembly) is malfunctioning.*3 There is a malfunction in a circuit outside of the certification ECU (smart key ECU assembly) circuit.	Certification ECU (smart key ECU assembly) Instrument panel junction block assembly No. 1 integration relay Wire harness or connector	DTC Output Confirmation Operation: Turn the power switch on (IG).

*1: Only detected while a malfunction is present and the power switch is on (IG).
*2: The IG circuit and IG hold circuit activate the IG relay.
*3: After the IG circuit turns on, even if the certification ECU (smart key ECU assembly) malfunctions, the IG hold circuit will maintain the power source mode in on (IG).

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected	Fail-safe Function when Malfunction Detected
The power switch cannot be turned on (IG) (the hybrid control system cannot be started).	The power source mode cannot be changed to on (IG).

Related Data List and Active Test Items

DTC No.	Data List and Active Test
B2271	Power Source Control IG Relay Monitor (Inside) Latch Circuit

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then select the vehicle type under manual mode and enter the following menus Body Electrical Smart Key. While using the Techstream, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function) uses the LIN communication system and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting. Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.
Click here
Before replacing the certification ECU (smart key ECU assembly), refer to Registration.
Click here
After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (POWER SOURCE)

(a) Disconnect the I1 certification ECU (smart key ECU assembly) connector.

*a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
I1-3 (+B) - Body ground	Power switch off	11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR IN CIRCUIT CONNECTED TO POWER SOURCE

OK

2.	CHECK HARNESS AND CONNECTOR (GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I1-18 (E) - Body ground	Always	Below 1 Ω

*a	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 4E instrument panel junction block assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
I1-15 (IG1D) - 4E-17	Always	Below 1 Ω
I1-15 (IG1D) or 4E-17 - Other terminals and body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.	CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - NO.1 INTEGRATION RELAY)

(a) Disconnect the 2A No. 1 integration relay connector.

(b) Disconnect the 4B instrument panel junction block assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
4B-13 - 2A-7	Always	Below 1 Ω
4B-13 or 2A-7 - Other terminals and body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.	INSPECT NO.1 INTEGRATION RELAY

(a) Inspect the No. 1 integration relay.

Click here

NG

REPLACE NO.1 INTEGRATION RELAY

OK

6.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 4F instrument panel junction block assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
4E-17 - 4F-3	Always	20 Ω or higher
4E-17 - 4B-13	Always	Below 1 Ω
4E-17 or 4F-3 - Other terminals	Always	10 kΩ or higher
4E-17 or 4B-13 - Other terminals	Always	10 kΩ or higher

OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY