C2191

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

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 write them down before removal.
- It is necessary to perform the initialization Initialization after the registration Registration of the transmitter IDs into the tire pressure warning ECU after the ECU has been replaced.

PROCEDURE

1. READ VALUE USING DATA LIST (VEHICLE SPEED)
(a) Turn the engine switch off.
(b) Connect Techstream to the DLC3.
(c) Turn the engine switch on (IG).
(d) Turn Techstream on.
(e) Check that the values indicated on the tester 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 display and on the 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 E81 ECU connector.
(b) Jack up the vehicle.
(c) Shift the lever to the neutral position.
(d) Turn the engine 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
3. CHECK HARNESS AND CONNECTOR (ECU - COMBINATION METER)




(a) Disconnect the E81 ECU connector.
(b) Disconnect the E20 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