Toyota Tundra Service Manual: Vehicle Speed Signal Circuit

WIRING DIAGRAM

PROCEDURE

1.	CHECK COMBINATION METER ASSEMBLY (SPEED SIGNAL)

(a) Disconnect the clearance warning ECU assembly connector.

(b) Using an oscilloscope, check the signal waveform of the combination meter assembly.

Measurement Condition

OK:

Refer to the illustration.

HINT:

As the vehicle speed increases, the wave length shortens.

Text in Illustration

Front view of wire harness connector

(to Clearance Warning ECU Assembly)

Waveform

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the J35 clearance warning ECU assembly connector.

(b) Disconnect the J28 combination meter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
J35-17 (SPD) - J28-29 (+S)	Always	Below 1 Ω
J35-17 (SPD) - Body ground	Always	10 kΩ or higher

GO TO METER / GAUGE SYSTEM

REPAIR OR REPLACE HARNESS OR CONNECTOR

Toyota Tundra Service Manual > Navigation System: Vehicle Speed Signal Circuit between Navigation Receiver Assembly and Combination Meter
DESCRIPTION The navigation receiver assembly receives a vehicle speed signal from the combination meter assembly to control the ASL function. HINT: A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transi ...

Toyota Tundra Owners Manual