Tire Pressure Monitoring (from 12/2010)

TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: C2191/91: Vehicle Speed Signal Error (Test Mode DTC)
C2191/91 - Vehicle Speed Signal Error (Test Mode DTC)

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 output only in test mode.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU using Techstream and note them down before removal.
* It is necessary to perform the initialization Initialization (from 12/2010) after the registration Registration (from 12/2010) of the transmitter IDs into the tire pressure warning ECU if the ECU has been replaced.

PROCEDURE

1. READ VALUE USING TECHSTREAM (VEHICLE SPEED)

(a) Make sure that the ignition switch is off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch on (IG).

(d) Turn the Techstream on.

(e) Check that the values indicated on the Techstream and on the combination meter are the same. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor:





OK:

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

NG -- INSPECT TIRE PRESSURE WARNING ECU

OK -- USE SIMULATION METHOD TO CHECK

2. INSPECT TIRE PRESSURE WARNING ECU

(a) Disconnect the D54 ECU connector.





(b) Jack up the vehicle.

(c) Shift the lever to the neutral position.

(d) Turn the ignition switch on (IG).

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

OK:





Tool Setting





HINT
The wavelength becomes shorter as the vehicle speed increases.

NG -- CHECK HARNESS AND CONNECTOR (ECU - COMBINATION METER)

OK -- REPLACE TIRE PRESSURE WARNING ECU Removal (from 12/2010)

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

(a) Disconnect the D54 ECU connector.





(b) Disconnect the E30 meter connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER Removal (from 12/2010)