ECU question

[PhatQ45]

My 95 Q45 ECU is dead. My friend got spare 93 ECU with TCS. I plug in engine start normal but I check the code manually there is one.. code 46 Secondary Throtle position sensor. Can I use this ECU instead spend few hundreds $$$ get another one. I dont want my engine stall on the road.

[Q45tech]

Depends on what "on the road means to you"I have spares of every electronic module in my Q45, When I drive beyond 100 miles away from inventorym I carry my emergency module and parts kit in trunk so I a not forced to wait for FEDEX or flatbed the car back home.

Obviously one cannot carry an engine or transmission so there is always some risk but that is managable.

[maxnix]

I guess one question is why is your ECU dead? These don't fail in normal operation.

Sounds like you got one out of a TCS equipped car. You can use the earlier 8 bit one, but it will not control your 2 speed auxiliary cooling fan correctly.

[PhatQ45]

I dont think it has anything to do with aux cooling fan. I check the 90-95 ECU diagram, TCS equipped Q45 has additional throttle motor sentor connect to trottle control, the ECU reply on this sensor sent nessary info to TCM (throttle control module). I test drive the car this morning she runs good and everything seem fine.

[maxnix]

The later 1994+ had a two speed auxiliary cooling fan. The earlier ones only had a one speed fan.

[PhatQ45]

you mean the fan in front of radiator?

[PhatQ45]

As long as cooling fan in front of radiator is running when it suppose to I guess it all good I keep it. THis ECU run better than my original ECU.

[qsiguy]

The cooling fan issue is irrelevant to this post. It is a minor issue with using an older ecu with a newer Q. The trouble code is as Brian stated, you have an ecu for a TCS car and you don't have TCS. It should not cause a problem other than the trouble code.

[PhatQ45]

The cooling fan issue is irrelevant to this post. It is a minor issue with using an older ecu with a newer Q. The trouble code is as Brian stated, you have an ecu for a TCS car and you don't have TCS. It should not cause a problem other than the trouble code.

The small black fan in front of radiator didn't come on at normal operating temprature. At what temperature this fan turn on? I guess my 95 cooling fan doesn't work with 93 ECU equipped with TCS

[PhatQ45]

So my new ECU I bought for $20 didn't turn on cooling fan but everything else work fine. Humm... how to fix this problem?? I dont want spend too much time rewire (not a wise idea i guess). I cut the wires connect to fan motor and wire it to constant power source. Now the cooling fan always on when engine is running. Problem solved