Toyota 4Runner: Vehicle Speed Signal Error (Test Mode DTC) (C2191/91)

Toyota 4Runner Service Manual / Suspension / Tire Pressure Monitoring / Tire Pressure Warning System / Vehicle Speed Signal Error (Test Mode DTC) (C2191/91)

DESCRIPTION

The tire pressure warning ECU receives a vehicle speed signal from the combination meter. This DTC is stored upon entering test mode and cleared when a vehicle speed signal of 20 km/h (12 mph) is detected for 3 seconds or more. This DTC is stored only in test mode.

DTC Code	Detection Condition	Trouble Area
C2191/91	The test mode procedure is performed.	Combination meter assembly Vehicle speed sensor circuit Tire pressure warning ECU

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU using the Techstream and write them down before removal.
It is necessary to perform registration of the transmitter IDs into the tire pressure warning ECU after the ECU and/or the tire pressure warning valve and transmitter has been replaced (See page ).

PROCEDURE

1.	READ VALUE USING TECHSTREAM (VEHICLE SPEED)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

(f) Check that the values indicated on the Techstream and on the combination meter are the same.

Tire Pressure Monitor

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Vehicle Speed	Vehicle speed/ min.: 0 km/h (0 mph) max.: 255 km/h (158 mph)	Almost same as actual vehicle speed	The speed indicated on the combination meter.

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Vehicle Speed

Vehicle speed/

min.: 0 km/h (0 mph)

max.: 255 km/h (158 mph)

Almost same as actual vehicle speed

The speed indicated on the combination meter.

OK:

Vehicle speed indicated on the Techstream and on the combination meter are the same.

USE SIMULATION METHOD TO CHECK

2.	INSPECT TIRE PRESSURE WARNING ECU (SPD SIGNAL)

(a) Disconnect the F7 ECU connector.

(b) Jack up the vehicle.

(d) Turn the ignition switch to ON.

(e) Check the waveform of the ECU connector using an oscilloscope while turning any of the wheels slowly.

OK:

Tester Connection	Switch Condition	Specified Condition
F7-2 (SPD) - F7-9 (GND)	Ignition switch ON	Correct waveform is as shown

Tool Setting

Item	Contents
Tool Setting	5 V/DIV., 20 ms/DIV.
Vehicle Condition	Any wheel is rotated slowly

HINT:

The wavelength becomes shorter as the wheels are rotated faster.

Text in Illustration

*a	Rear view of wire harness connector (to Tire Pressure Warning ECU)

REPLACE TIRE PRESSURE WARNING ECU

3.	CHECK HARNESS AND CONNECTOR (ECU - COMBINATION METER)

(a) Disconnect the F7 ECU connector.

(b) Disconnect the F14 meter connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
F7-2 (SPD) - F14-28 (+S)	Always	Below 1 Ω
F7-2 (SPD) - Body ground	Always	10 kΩ or higher

GO TO METER/GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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