Toyota Tacoma (2015-2018) Service Manual: Power Source Mode does not Change to ON (IG)

Toyota Tacoma (2015-2018) Service Manual / 2gr-fks Starting / Smart Key System(for Start Function) / Power Source Mode does not Change to ON (IG)

DESCRIPTION

If the engine switch is pressed with the electrical key transmitter sub-assembly in the cabin, the certification ECU (smart key ECU assembly) receives a signal and changes the power source mode.

HINT:

When the cable is disconnected and reconnected to the negative (-) battery terminal, the power source mode returns to the state it was in before the cable was disconnected.

WIRING DIAGRAM

Refer to Power Source Mode does not Change to ON (IG and ACC) (See page CAUTION / NOTICE / HINT ).

CAUTION / NOTICE / HINT

NOTICE:

When using the Techstream with the engine 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 an intervals of 1.5 seconds or less to maintain communication between the Techstream and the vehicle.
The smart key system (for Start Function) uses a multiplex communication system (LIN communication system) and the CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting.
Click here

Troubleshoot the smart key system (for Start Function) after confirming that the communication systems are functioning properly.
Make sure that no DTCs are output. If any DTCs are output, proceed to the Diagnostic Trouble Code Chart (See page ).
If the smart key system is disabled through the customize function, enable the system before performing troubleshooting (See page ).
Before replacing the certification ECU (smart key ECU assembly), refer to the smart key system (for Start Function) precaution (See page ).
Inspect the fuses of circuits related to this system before performing the following inspection procedure.
After completing repairs, confirm that the problem does not occur.

Related Data List and Active Test Items

Problem Symptom	Data List and Active Test
Power source mode does not change to on (IG) but does change to on (ACC)	Power Source Control Power Supply Condition IG Relay Monitor (Inside) IG Relay Monitor (Outside) IG Circuit Starting Control Ignition

PROCEDURE

1.	CHECK FOR DTC

(a) Using the Techstream, check for certification ECU (smart key ECU assembly) DTCs (See page Result ).

Result

Result	Proceed to
DTCs are not output	A
Smart key system (for Start Function) DTCs are output	B

GO TO DIAGNOSTIC TROUBLE CODE CHART

2.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - DRIVER SIDE JUNCTION BLOCK)

(a) Disconnect the C27 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the 1A and 1D driver side junction block connectors.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C27-3 (IG1D) - 1A-16	Always	Below 1 Ω
1D-5 - Body ground	Always	Below 1 Ω
C27-3 (IG1D) or 1D-5 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - IG2-MAIN RELAY)

(a) Disconnect the C27 certification ECU (smart key ECU assembly) connector.

(b) Remove the IG2-MAIN relay from the engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C27-3 (IG1D) - 1 (IG2-MAIN relay)	Always	Below 1 Ω
2 (IG2-MAIN relay) - Body ground	Always	Below 1 Ω
C27-3 (IG1D) or 1 (IG2-MAIN relay) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.	CHECK DRIVER SIDE JUNCTION BLOCK (IG1 NO. 1, IG1 NO. 2, IG1 NO.3 RELAY)

(a) Remove the driver side junction block (See page Text in Illustration ).

Text in Illustration

Component without harness connected

(Driver Side Junction Block)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1A-16 - 1D-5	20°C (68°F)	87.32 to 127.14 Ω
1K-1 - 1F-1	Battery voltage applied to terminals 1A-16 and 1D-5	Below 1 Ω
1K-1 - 1F-1	Battery voltage not applied to terminals 1A-16 and 1D-5	10 kΩ or higher
1K-1 - 1D-4	Battery voltage applied to terminals 1A-16 and 1D-5	Below 1 Ω
1K-1 - 1D-4	Battery voltage not applied to terminals 1A-16 and 1D-5	10 kΩ or higher
1K-1 - 1F-12	Battery voltage applied to terminals 1A-16 and 1D-5	Below 1 Ω
1K-1 - 1F-12	Battery voltage not applied to terminals 1A-16 and 1D-5	10 kΩ or higher

REPLACE DRIVER SIDE JUNCTION BLOCK

5.	INSPECT IG2-MAIN RELAY

(a) Remove the IG2-MAIN relay.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 - 5	Battery voltage applied to terminals 1 and 2	Below 1 Ω
3 - 5	Battery voltage not applied to terminals 1 and 2	10 kΩ or higher

Text in Illustration

*1	IG2-MAIN Relay

REPLACE IG2-MAIN RELAY

6.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Reconnect the certification ECU (smart key ECU assembly) connector.

(b) Install the driver side junction block.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
C27-3 (IG1D) - Body ground	Engine switch on (ACC) → Engine switch on (IG)	1 V or less → 9 V or higher

Text in Illustration

*a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

USE SIMULATION METHOD TO CHECK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Power Source Mode does not Change to ON (IG and ACC)

DESCRIPTION If any of the following operations are performed, the certification ECU (smart key ECU assembly) receives a signal, and changes the power source mode. With the electrical key tr ...

Power Source Mode does not Change to ON (ACC)

DESCRIPTION If the engine switch is pressed with the electrical key transmitter sub-assembly in the cabin, the certification ECU (smart key ECU assembly) receives a signal and changes the power s ...

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