Toyota 4Runner: Speed Signal Circuit

Toyota 4Runner Service Manual / Vehicle Interior / Meter / Gauge / Display / Meter / Gauge System / Speed Signal Circuit

DESCRIPTION

The vehicle speed signal consists of pulses sent to the combination meter assembly from the master cylinder solenoid (skid control ECU)*1 or skid control ECU (brake actuator assembly)*2.

*1: for 4WD
*2: for 2WD

WIRING DIAGRAM

PROCEDURE

1.	CHECK ECU TERMINAL VOLTAGE (INPUT VOLTAGE)

(a) Disconnect the F14 combination meter assembly connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
F14-28 (+S) - Body ground	Ignition switch ON	4.5 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Combination Meter Assembly)

GO TO STEP 5

2.	CHECK COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)

(a) for 4WD:

(1) Disconnect the A6 master cylinder solenoid (skid control ECU) connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A6-12 (SP1) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Master Cylinder Solenoid (Skid Control ECU))

(b) for 2WD:

(1) Disconnect the A53 skid control ECU (brake actuator assembly) connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A53-11 (SP1) - Body ground	Ignition switch ON	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

GO TO STEP 4

3.	CHECK COMBINATION METER ASSEMBLY (SPEED SIGNAL)

(a) Check the input waveform.

(1) Reconnect the F14 combination meter assembly connector.

(2) Remove the combination meter assembly with the connector(s) still connected.

(3) Connect an oscilloscope to terminal F14-29 (SI) and body ground.

(4) Turn the ignition switch to ON.

(5) Check the signal waveform according to the condition(s) in the table below.

Measurement Condition

Item	Condition
Terminal No. (Symbol)	F14-29 (SI) - Body ground
Tool setting	5 V/DIV., 20 ms./DIV.
Condition	Driving at approx. 20 km/h (12 mph)

OK:

The waveform displayed is as shown in the illustration.

HINT:

When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

Result

Result	Proceed to
OK	A
NG (for 4WD)	B
NG (for 2WD)	C

REPLACE COMBINATION METER ASSEMBLY

REPLACE MASTER CYLINDER SOLENOID (SKID CONTROL ECU)

REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

4.	CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SKID CONTROL ECU)

(a) Disconnect the F14 combination meter assembly connector.

(b) Disconnect the A6 master cylinder solenoid (skid control ECU )*1 or A53 skid control ECU (brake actuator assembly)*2 connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F14-29 (SI) - A6-12 (SP1)1 F14-29 (SI) - A53-11 (SP1)2	Always	Below 1 Ω
A6-12 (SP1) - Body ground1 A53-11 (SP1) - Body ground2	Always	10 kΩ or higher

Tester Connection

Condition

Specified Condition

F14-29 (SI) - A6-12 (SP1)*1

F14-29 (SI) - A53-11 (SP1)*2

Always

Below 1 Ω

A6-12 (SP1) - Body ground*1

A53-11 (SP1) - Body ground*2

Always

10 kΩ or higher

*1: for 4WD
*2: for 2WD

REPLACE COMBINATION METER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - NO. 4 JUNCTION BLOCK)

(a) Disconnect the F14 combination meter assembly connector.

(b) Disconnect the 4B No. 4 junction block connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F14-28 (+S) - 4B-20	Always	Below 1 Ω
F14-28 (+S) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK)

(a) Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.

HINT:

If voltage is not present, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.

(1) Disconnect the 4A No. 4 junction block connector.

Text in Illustration

No. 4 Junction Block

Front view of wire harness connector

(to No. 4 Junction Block)

(2) Disconnect the 4C No. 4 junction block connector.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
4C-16 - Body ground	Ignition switch ON	4.5 to 14 V
4B-8 - Body ground	Ignition switch ON	4.5 to 14 V
4A-90 - Body ground	Ignition switch ON	4.5 to 14 V

Result

Result	Proceed to
Voltage is not present in one circuit	A
Voltage is present in all the circuits	B

REPLACE NO. 4 JUNCTION BLOCK

7.	SYSTEM CHECK

(a) Select the circuit for which voltage was not present in the previous step.

Result

Tester Connection	System that Uses the Circuit	Proceed to
4C-16 - Body ground	SFI system, smart key system1, safety connect system2, voltage inverter1, intuitive parking assist system3	A
4B-8 - Body ground	Tire pressure warning system	B
4A-90 - Body ground	Audio and visual system or navigation system	C

*1: w/ Smart Key System
*2: w/ Safety Connect System
*3: w/ Intuitive Parking Assist System

GO TO STEP 16

GO TO STEP 17

8.	CHECK HARNESS AND CONNECTOR (NO. 4 JUNCTION BLOCK - NO. 5 JUNCTION BLOCK)

(a) Disconnect the 4C No. 4 junction block connector.

(b) Disconnect the 5B No. 5 junction block connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
4C-16 - 5B-25	Always	Below 1 Ω
4C-16 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	CHECK HARNESS AND CONNECTOR (NO. 5 JUNCTION BLOCK)

(a) Disconnect the 5A No. 5 junction block connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
5B-2 - 5A-13	Always	Below 1 Ω
5B-2 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.	CHECK HARNESS AND CONNECTOR (NO. 5 JUNCTION BLOCK)

(a) Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.

(1) Disconnect the 5C No. 5 junction block connector.

Text in Illustration

No. 5 Junction Block

Front view of wire harness connector

(to No. 5 Junction Block)

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
5B-14 - Body ground	Ignition switch ON	4.5 to 14 V
5C-1 - Body ground*1	Ignition switch ON	4.5 to 14 V
5A-1 - Body ground*1	Ignition switch ON	4.5 to 14 V
5A-38 - Body ground*2	Ignition switch ON	4.5 to 14 V
5A-73 - Body ground*3	Ignition switch ON	4.5 to 14 V

*1: w/ Smart Key System
*2: w/ Safety Connect System
*3: w/ Intuitive Parking Assist System

Result

Result	Proceed to
Voltage is not present in one circuit	A
Voltage is present in all the circuits	B

REPLACE NO. 5 JUNCTION BLOCK

11.	SYSTEM CHECK

(a) Select the circuit for which voltage was not present in the previous step.

Result

Tester Connection	System that Uses the Circuit	Proceed to
5B-14 - Body ground	SFI system	A
5C-1 - Body ground*1	Voltage inverter	B
5A-1 - Body ground*1	Smart key system	C
5A-38 - Body ground*2	Safety connect system	D
5A-73 - Body ground*3	Intuitive Parking Assist System	E

*1: w/ Smart Key System
*2: w/ Safety Connect System
*3: w/ Intuitive Parking Assist System

GO TO STEP 13

GO TO STEP 14

GO TO STEP 15

GO TO STEP 20

12.	CHECK HARNESS AND CONNECTOR (ECM CIRCUIT)

(a) Disconnect the F51 ECM connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F51-18 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

13.	CHECK HARNESS AND CONNECTOR (VOLTAGE INVERTER ASSEMBLY CIRCUIT)

(a) Disconnect the N19 voltage inverter assembly connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N19-2 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE VOLTAGE INVERTER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU CIRCUIT)

(a) Disconnect the F80 power management control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F80-23 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE POWER MANAGEMENT CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

15.	CHECK HARNESS AND CONNECTOR (TELEMATICS TRANSCEIVER CIRCUIT)

(a) Disconnect the F39 telematics transceiver connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F39-10 (SPDP) - Body ground	Always	10 kΩ or higher

REPLACE TELEMATICS TRANSCEIVER

REPAIR OR REPLACE HARNESS OR CONNECTOR

16.	CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU CIRCUIT)

(a) Disconnect the F7 tire pressure warning ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F7-2 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE TIRE PRESSURE WARNING ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	SYSTEM CHECK

(a) Proceed to the appropriate inspection based on the components of the vehicle.

Component

Component	Proceed to
for Navigation Receiver Type	A
for Radio and Display Type	B
for 9 Speakers Type	C

GO TO STEP 19

GO TO STEP 21

18.	CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER CIRCUIT)

(a) Disconnect the G37 navigation receiver connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G37-17 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE NAVIGATION RECEIVER ASSEMBLY

REPAIR OR REPLACE HARNESS AND CONNECTOR

19.	CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER CIRCUIT)

(a) Disconnect the G49 radio and display receiver connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
G49-17 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

20.	CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU CIRCUIT)

(a) Disconnect the F95 clearance warning ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
F95-5 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE CLEARANCE WARNING ECU ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

21.	CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY)

(a) Disconnect the N11 stereo component amplifier connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N11-11 (SPD) - Body ground	Always	10 kΩ or higher

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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