12 replies to this topic

[Doctor Ed]

Hey guys, the standard coolant temp sensor on a turbo... or the other way around - the turbo stack instrument... what’s the coolant temp sensor voltage range? Whatever it is it’s not the same as the A20. So need to hack another sensor onto the motor somewhere.

Any idea which other motors run the same sensor

Alternatively if anyone has a spare original sensor?

Cheers
Ed

Edited by Doctor Ed, 21 July 2018 - 07:57 AM.

[siztenboots]

https://www.carparts...4f259897

 

the one on the engine block

[vocky]

Saab B207 also uses a similar sensor for the coolant

[Doctor Ed]

No idea what the voltage range is?

[vocky]

I think on my Omex it was 1v to 4.8v

[Exmantaa]

Ehhhh... You probably have issues with the Stack reading the temperature signa?

OEM Stack dash needs a PWM signal from the ecu, not a proportional voltage...

[Doctor Ed]

Really? Well that’s a pain in the ass

[siztenboots]

maybe the turbo dash just uses a plain old dumb NTC resistor

[Arno]

Coolant temperature is transmitted using a PWM signal from the ECU.

 

ECU has a coolant temperature sensor/NTC (B61) that connects on pin 38: https://www.speedste... Z20LET - 1.pdf

 

It processes the data and connects via X3 to the dash pin A6, just like the Z22SE: https://www.speedste...m/Instument.pdf

 

Both the Motronic (Z20LET) as the Multec (Z22SE) do it this way. AFAIK there's no difference in this respect.

 

Alternative circuit here: https://arc.seloc.or...ge=2#pid5242375

 

Or you can implement it probably with an Arduino or even (severe overkill) a Pi to generate the correct PWM signal from an NTC sensor input.

 

Bye, Arno.

[siztenboots]

Coolant temperature is transmitted using a PWM signal from the ECU.

 

ECU has a coolant temperature sensor/NTC (B61) that connects on pin 38: https://www.speedste... Z20LET - 1.pdf

 

It processes the data and connects via X3 to the dash pin A6, just like the Z22SE: https://www.speedste...m/Instument.pdf

 

Both the Motronic (Z20LET) as the Multec (Z22SE) do it this way. AFAIK there's no difference in this respect.

 

Alternative circuit here: https://arc.seloc.or...ge=2#pid5242375

 

Or you can implement it probably with an Arduino or even (severe overkill) a Pi to generate the correct PWM signal from an NTC sensor input.

 

Bye, Arno.

 

this ties is with the work I did on the turbo loom and ecu pin-outs

 

so are we saying that there is no second water temp sensor at the front?

[Exmantaa]

We made a similar circuit with a PIC to make the PWM signal to the Stack.

[Doctor Ed]

im inclined to ignore the temp guage in the stack then, and just OBD this stuff to my phone

[Exmantaa]

im inclined to ignore the temp guage in the stack then, and just OBD this stuff to my phone

 

 

That is BY FAR the easiest solution! and monitor together with IAT.

 

We build the circuit with a PIC and calibrated temps with a lookup table, but we only installed that on my mates car (LSJ ecu). I'm running already 2 (maybe 3?) years without a fuctioning ECT gauge on my Stack dash. One thing less to worry about.