WS2 Flash Codes

Modern ECU is capable to provide self-diagnostics. It records and stores faults in the memory. To obtain recorded information technician can read these codes from instrumental panel via flashing light. For Toyota 4A-FE check engine light is used for codes reading. The pattern of flashing pulses describes the structure of codes and helps to understand how to read and interprit a signal.

To activate trouble codes reading TE1 and E1 pins in the diagnosis box must be connected. The table with fault were found is below

Code number	System affected	Condition described
41	TPS	Open circuit in TPS circuitry
31	MAP	Fault in MAP sensor signal reading
24	IATC	Open circuit in air temperature sensor wiring

All the codes from the table above were used to localise the faulty devices, connection e.t.c. So that, thereby codes reading we can save time during diagnosis. In all our cases problems were related with unplugged connectors. 

Ones every devises were connected properly engine ran smoothly without warning lamp flashing. Fault codes can be erased from memory by disconnecting battery for a several minutes. However, this method works for this particular engine. But for other modification the manual must be read. 

With fault we found during experiment air fuel mixture would be rich. Engine performance definitely would be affected. TPS reading could provoke  flat spot during acceleration.

N.B. Trouble codes table does not say to you that this or those sensor is faulty. It names a circuit in which this sensor is wired. Next step is to analise this circuit by means of measuring voltdrop, oscilloscope patterns analising e.t.c.