6G Celicas Forums

Hi guys, so im converting my Mr2 turbo rev1 to use an ST205 Ecu.
I made a patch cable so i could swap back if needed.
Started up first time then wouldnt idle, did this a couple times.
Got fault code 21, expected as im using the old 1 wire lambda.

Then i revved a bit more, while still, and got a string of fault codes, 21, 22 24, maybe 26, and another which i missed as i got distracted not 54 as ive already done the resistor mod for the charge cooler stuff.

Pretty certain my patch cable is correct.
Then i decide start the car again, turn key and de-immobilise (toad alarm) and the three engine lights etc dont come on, and it doesnt even do anything when i turn the key? Weird as i didnt change anything.

Swapped back to old ecu and started fine.

So i thinking that my lambda needs to be swapped for 21 and would that of caused it to run rich and give 26? And wrong lambda might if caused the no idle?
But the water temp is in same place as on the Mr2 so that should of been fine? (Coolant temp?) So not sure why 22.

And my IAT, 24, the one i have looks exact same as the engine bay temp sensor with same connection? Is that correct?

Thanks all,
Dan
(ps. I used to have a celica, should of kept it)

the ecu alone is useless to you without all the sensors in the head and manifolds

map sensor
manifold temp sensor (and the manifold itself which has the port for it)
o2 sensor
tps maybe, (use entire Gen3 throttlebody)
injectors/fuel reg (entire rail)

your best bet will be to take an entire st205 engine loom and repin where necessary with st185/sw20/gen2 plugs


i have no idea how you could have embarked on such a project without this basic knowledge?

Just to inform you, i embarked on the project with all of the components required but didnt really feel the need to list them here because as you say, its basic knowledge.
If i had blindly gone into it i wouldnt of been able to bypass fault code 54 either would i?
You missed off IAT, and it works fine on my old Tps.
All running on the St205 ecu, my problem was loose connections in the repinned harness.
Now making a set up for charge cooling the Mr2

This post has been edited by Danohosko: Oct 30, 2013 - 4:52 AM

IAT as in the plastic black plug in the air box in a celica, and attached to the top of the "bonnet" on the mr2?

ECU doesn't care too much for that black plastic air temp sensor, its the manifold air temp sensor that the code will be referring to. your confusion between the two air temp sensors lead me to believe you had no idea about the manifold temp sensor so i had to ask, did you even have all the right st205 sensors

code 54 is the most commonly documented st205 thing around, because 99% of st205 check engine light situations are from the water level sensor. bridging a circuit open/circuit close sensor isnt exactly rocket science so your point is moot