Smart Key System (for Start Function)

THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function): TERMINALS OF ECU

TERMINALS OF ECU

1. CHECK MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)









(a) Disconnect the E50, E51, E52, 2E and 2C ECU connectors.
(b) Measure the voltage and resistance of the wire harness side connector.





If the result is not as specified, there may be a malfunction on the wire harness side.
(c) Reconnect the ECU connectors.
(d) Measure the voltage of the connector.









HINT: *1: Voltage is output only when the engine is cranking.
*2: Voltage is output for 0.3 seconds when the engine is cranking to start. Disconnect the B31 connector from the ECM and starter cut relay before measuring the voltage.
*3: Remove the starter cut relay before measuring the voltage.
*4: for TMC Made
*5: for except TMC Made
If the result is not as specified, the ECU may have a malfunction.

(e) Using an oscilloscope, check the signal waveform of the ECU.




(1) Waveform 1





HINT: As the vehicle speed increases, the wavelength shortens.




(2) Waveform 2





HINT: As the engine revolution speed increases, the wavelength shortens.




(3) Waveform 3






2. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)





(a) Disconnect the E36 ECU connector.
(b) Measure the voltage and resistance of the wire harness side connector.





If the result is not as specified, there may be a malfunction on the wire harness side.
(c) Reconnect the ECU connector.
(d) Measure the voltage of the connector.





HINT: *1: for TMC Made
*2: for except TMC Made
If the result is not as specified, the ECU may have a malfunction.

3. CHECK ECM





(a) Disconnect the B31 and A50 ECM connectors.
(b) Measure the voltage and resistance of the wire harness side connectors.






(c) Reconnect the ECM connectors.
(d) Measure the voltage of the connectors.





HINT: *: Voltage is output only when the engine is cranking.
If the result is not as specified, the ECM may have a malfunction.





(e) Using an oscilloscope, check the signal waveform of the ECM.





HINT: As the vehicle speed increases, the wavelength shortens.

4. CHECK STEERING LOCK ECU





(a) Disconnect the E39 ECU connector.
(b) Measure the voltage and resistance of the wire harness side connector.





If the result is not as specified, there may be a malfunction on the wire harness side.
(c) Reconnect the E39 ECU connector.
(d) Measure the voltage of the connector.





If the result is not as specified, the ECU may have a malfunction.
HINT: *1: for TMC Made
*2: for except TMC Made