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

Toyota Tacoma 2015-2018 Service Manual / 2gr-fks Starting / Smart Key System(for Start Function) / 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 transmitter sub-assembly in the cabin, the engine switch is pressed.
When the battery of the electrical key transmitter sub-assembly is depleted, the brake pedal is depressed and the electrical key transmitter sub-assembly is held near the engine switch.
When the smart key cancel function has been canceled on the customization menu, the brake pedal is depressed and the electrical key transmitter sub-assembly is held near the engine switch.

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.
If the room oscillator does not recognize the key, the cause of the malfunction may be stored in the certification ECU (smart key ECU assembly) (See page ).
If the cause of the malfunction is stored in the certification ECU (smart key ECU assembly), the following table is helpful in checking whether or not the malfunction was caused by wave interference.

Radio Wave Interference:

Problem Symptom	Data List Item
Operating Engine Switch / Key RF Signal Interference	When the engine switch was operated, the electrical key transmitter sub-assembly could not be confirmed due to wave interference. Therefore, the output frequency was switched to the other channel (changed from channel 1 to channel 2 or from channel 2 to channel 1). If the cause of the malfunction has not been stored but any devices that can cause wave interference in the cabin have been removed and the room oscillator successfully recognizes the key, the possibility of wave interference is high.

Problem Symptom

Data List Item

Operating Engine Switch / Key RF Signal Interference

When the engine switch was operated, the electrical key transmitter sub-assembly could not be confirmed due to wave interference. Therefore, the output frequency was switched to the other channel (changed from channel 1 to channel 2 or from channel 2 to channel 1).
If the cause of the malfunction has not been stored but any devices that can cause wave interference in the cabin have been removed and the room oscillator successfully recognizes the key, the possibility of wave interference is high.

WIRING DIAGRAM

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 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 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) or electrical key transmitter sub-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 Item	Active Test Item
Power source mode does not change to on (IG) or on (ACC)	Power Source Control Start Switch1 Start Switch2 Power Supply Condition IG Relay Monitor(Inside) IG Relay Monitor (Outside) Latch Circuit ACC Relay Monitor	-

PROCEDURE

1.	CHECK ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

(a) Press a switch of the electrical key transmitter sub-assembly.

OK:

The electrical key transmitter sub-assembly LED illuminates.

GO TO STEP 14

2.	READ VALUE USING TECHSTREAM (KEY LOW BATTERY)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Body Electrical / Smart Key / Data List.

(e) Read the Data List according to the display on the Techstream.

Smart Key

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Key Low Battery	Transmitter battery depleted / Yes or No	Yes: Transmitter battery depleted No: Transmitter battery not depleted	The electrical key transmitter sub-assembly sends voltage information to the certification ECU (smart key ECU assembly) when it is transmitting. The certification ECU (smart key ECU assembly) displays "Yes" for the "Key Low Battery" item of the Data List when this voltage information indicates 2.2 V or less. This Data List item should be checked when the electrical key transmitter sub-assembly is at room temperature (example: at -20°C (-4°F), "Yes" may be displayed even if the transmitter battery is new).

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Key Low Battery

Transmitter battery depleted / Yes or No

Yes: Transmitter battery depleted

No: Transmitter battery not depleted

The electrical key transmitter sub-assembly sends voltage information to the certification ECU (smart key ECU assembly) when it is transmitting. The certification ECU (smart key ECU assembly) displays "Yes" for the "Key Low Battery" item of the Data List when this voltage information indicates 2.2 V or less. This Data List item should be checked when the electrical key transmitter sub-assembly is at room temperature (example: at -20°C (-4°F), "Yes" may be displayed even if the transmitter battery is new).

OK:

"No" is displayed on the Techstream screen.

REPLACE TRANSMITTER BATTERY

3.	CHECK POWER SOURCE MODE

(a) Get into the vehicle while carrying an electrical key transmitter sub-assembly.

(b) Move the shift lever to P.

Result

Result	Proceed to
The power source mode does not change	A
The power source mode changes	B

END (AFFECTED BY WAVE INTERFERENCE)

4.	CHECK SMART KEY SYSTEM (for StartFunction)

(a) Remove the transmitter battery from the electrical key transmitter sub-assembly.

(b) With the brake pedal depressed, hold the electrical key transmitter sub-assembly near the engine switch and check if the power source mode changes.

OK:

The power source mode changes.

Text in Illustration

*1	Engine Switch
*2	Electrical Key Transmitter Sub-assembly

Result

Result	Proceed to
The power source mode does not change	A
The power source mode changes	B

HINT:

If the power source mode changes, the cabin verification is malfunctioning.

GO TO STEP 11

5.	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

6.	CHECK HARNESS AND CONNECTOR (POWER SOURCE)

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

7.	CHECK HARNESS AND CONNECTOR (GROUND)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Disconnect the C29 and C27 certification ECU (smart key ECU assembly) connectors.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C29-9 (ACCD) - 1A-28	Always	Below 1 Ω
C27-3 (IG1D) - 1A-16	Always	Below 1 Ω
1D-5 - Body ground	Always	Below 1 Ω
C29-9 (ACCD) or 1A-28 - Body ground	Always	10 kΩ or higher
C27-3 (IG1D) or 1D-16 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Remove the driver side junction block (See page (b) Measure the resistance according to the value(s) in the table below. ).

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

Text in Illustration

Component without harness connected

(Driver Side Junction Block)

Standard Resistance:

Tester Connection	Condition	Specified Condition
1A-16 - 1D-5	20°C (68°F)	87.32 to 127.14 Ω
1A-28 - 1D-5	20°C (68°F)	130.92 to 190.74 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
1K-1 - 1F-24	Battery voltage applied to terminals 1A-28 and 1D-5	Below 1 Ω
1K-1 - 1F-24	Battery voltage not applied to terminals 1A-28 and 1D-5	10 kΩ or higher

REPLACE DRIVER SIDE JUNCTION BLOCK

10.	CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Install the driver side junction block (See page (b) Connect the C29 and C27 certification ECU (smart key ECU assembly) connectors. ).

(b) Connect the C29 and C27 certification ECU (smart key ECU assembly) connectors.

Text in Illustration

Component with harness connected

(Certification ECU (Smart Key ECU Assembly))

Power Source Control

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Power Supply Condition

Power supply state / All OFF, ACC ON, IG ON or ST ON

All OFF: Engine switch off (ACC and IG)

ACC ON: Engine switch on (ACC)

IG ON: Engine switch on (IG)

ST ON: Sending engine start request signal

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
C27-3 (IG1D) - Body ground	Engine switch off	1 V or less
	Engine switch on (ACC)	1 V or less
	Engine switch on (IG)	9 V or higher
C29-9 (ACCD) - Body ground	Engine switch off	1 V or less
	Engine switch on (ACC)	8.5 V or higher
	Engine switch on (IG)	8.5 V or higher

Result

Result	Proceed to
NG	A
OK	B

USE SIMULATION METHOD TO CHECK

11.	READ VALUE USING TECHSTREAM (START SWITCH1, START SWITCH2)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Body Electrical / Power Source Control / Data List.

(e) Read the Data List according to the display on the Techstream.

Power Source Control

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Start Switch1

Engine switch 1 status / ON or OFF

ON: Engine switch pressed

OFF: Engine switch not pressed

If the engine switch is pressed for a short time, the display may not change.
Use this item to determine whether the engine switch input signal is malfunctioning.

Start Switch2

Engine switch 2 status / ON or OFF

ON: Engine switch pressed

OFF: Engine switch not pressed

Backup for engine switch 1. However, when the engine switch is pressed and held, the control functions only when both engine switch 1 and 2 are normal.
Behaves the same way as engine switch 1.

OK:

The Techstream display changes correctly in response to the engine switch operation.

Result

Result	Proceed to
NG	A
OK	B

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

12.	INSPECT ENGINE SWITCH

(a) Remove the engine switch (See page (b) Inspect the engine switch (See page ). ).

(b) Inspect the engine switch (See page ).

REPLACE ENGINE SWITCH

13.	CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE SWITCH)

(a) Disconnect the C29 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the E28 engine switch connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
C29-16 (SSW1) - E28-5 (SS1)	Always	Below 1 Ω
C29-18 (SSW2) - E28-1 (SS2)	Always	Below 1 Ω
C29-12 (AGND) - E28-6 (AGND)	Always	Below 1 Ω
C29-16 (SSW1) or E28-5 (SS1) - Body ground	Always	10 kΩ or higher
C29-18 (SSW2) or E28-1 (SS2) - Body ground	Always	10 kΩ or higher
C29-12 (AGND) or E28-6 (AGND) - Body ground	Always	10 kΩ or higher

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	INSPECT TRANSMITTER BATTERY

(a) Inspect the transmitter battery (See page ).

NOTICE:

Do not wrap the lead wire around a terminal, wedge it between terminals, or solder it. The terminal may be deformed or damaged, and the transmitter battery will not be able to be installed correctly.

REPLACE ELECTRICAL KEY TRANSMITTER SUB-ASSEMBLY

REPLACE TRANSMITTER BATTERY

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