Toyota Venza: Speed Signal Circuit

Toyota Venza Service Manual / Lighting (ext) / Lighting System / Speed Signal Circuit

DESCRIPTION

The headlight leveling ECU assembly receives the vehicle speed signal from the combination meter assembly.

HINT:

A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter. The signal is changed to a pulse signal at the transistor in the combination meter. Each ECU controls the respective system based on the pulse signal.
If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the diagram below will not operate normally.

WIRING DIAGRAM

1. for 2GR-FE

2. for 1AR-FE

PROCEDURE

1.	CHECK COMBINATION METER SYSTEM

(a) The circuits that send vehicle speed signals to this system are inspected in the meter section (See page ).

(b) During inspection for the meter system, if there is an instruction that indicates to go back to inspections for the lighting system, proceed to the next step.

2.	CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the E1 combination meter assembly connector.

(b) Disconnect the A40 headlight leveling ECU assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A40-16 (SPDR) - E1-16 (+S)	Always	Below 1 Ω

Text in Illustration

Front view of wire harness connector

(to Combination Meter Assembly)

Front view of wire harness connector

(to Headlight Leveling ECU Assembly)

REPAIR OR REPLACE HARNESS OR CONNECTOR (WIPER RELAY - COMBINATION METER)

3.	INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

(a) Check the output waveform.

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

(2) Connect an oscilloscope to terminal E1-16 (+S) and body ground.

(3) Turn the ignition switch to ON.

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

Item	Condition
Tool setting	5 V/DIV., 20 ms./DIV.
Vehicle condition	Driving at approx. 20 km/h (12 mph)

OK:

The waveform is displayed as shown in the illustration.

Text in Illustration

*1	Component with harness connected (Combination Meter Assembly)

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.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPLACE COMBINATION METER ASSEMBLY

Indicator Circuit

DESCRIPTION The headlight beam level control system indicator light in the combination meter assembly comes on for approximately 3 seconds when the ignition switch is turned to ON. The indicator ...

Inner Rear View Mirror Power Source Circuit

DESCRIPTION This circuit detects the state of the ignition switch, and sends it to the inner rear view mirror assembly. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for ci ...

Other materials about Toyota Venza:

How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT: Use the following procedure to troubleshoot the lighting system. *: Use the Techstream. PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP NEXT ...

Starter Relay Circuit High (P0617)
MONITOR DESCRIPTION While the engine is being cranked, battery voltage is applied to terminal STA of the ECM. If the ECM detects the Starter Control (STA) signal while the vehicle is being driven, it determines that there is a malfunction in the STA circu ...

Precaution
PRECAUTION 1. PRECAUTION FOR DISCONNECTING THE BATTERY CABLE NOTICE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected: System See Procedure ...