Engine Speed Signal Error (Test Mode DTC) - Tire Pressure Monitoring

TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: C2194/94: Engine Speed Signal Error (Test Mode DTC)
C2194/94 - Engine Speed Signal Error (Test Mode DTC)

DESCRIPTION

The tire pressure warning ECU receives an engine speed signal from the ECM. This DTC is stored upon entering test mode, and cleared when the engine speed signal of 1000 rpm is detected for 3 seconds or more. This DTC is output only in test mode.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
It is necessary to register the transmitter IDs after replacing a tire pressure warning valve and transmitter and/or the tire pressure warning ECU Programming and Relearning.

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE SPEED)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch ON.

(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:

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

NG -- INSPECT TIRE PRESSURE WARNING ECU (TACH SIGNAL)

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

2. INSPECT TIRE PRESSURE WARNING ECU (TACH SIGNAL)

(a) Disconnect the E56 ECU connector.





(b) Start the engine.

(c) Check the waveform of the ECU connector using an oscilloscope, while idling the engine.

OK:





Tool Setting





HINT
The wavelength becomes shorter as the engine speed increases.

NG -- CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - ECM)

OK -- REPLACE TIRE PRESSURE WARNING ECU Removal

3. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - ECM)

(a) Disconnect the E56 ECU connector.





(b) Disconnect the A9 ECM connector.

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

(1) for 2GR-FE:

Standard resistance:





(2) for 2AR-FE:

Standard resistance:





Result:





C -- REPLACE ECM (for 2GR-FE) Removal

B -- REPLACE ECM (for 2AR-FE) Removal

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR