Water temp fault s40

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Motoroche
Posts: 4
Joined: Mon Feb 01, 2016 5:05 am
ECU Model: S40 Pro
Firmware Version: 79.02

Water temp fault s40

Post by Motoroche »

I'm having trouble with my s40 reading water temp, which is a real pain as my cold start will not work and the electric radiator fan cannot be activated or controlled through the ecu.
The gauge on dtaswin is red and faulted to 60 degrees.
I have checked the temp sensor and tried others and also checked out the wiring from the temp sensor to the ecu plug. The two sensor plug wires have good continuity and when connected to the sensor I'm getting correct resistance at the ecu plug.
I checked for voltage at the water temp sensor plug and got a 0v reading, then I tested the air temp sensor plug which is working fine and I got a reading of 5v which I should be getting for the water temp sensor too I guess?
So its sounds like a problem with my s40, what would be the next step to fixing it, can the s40 be repaired?
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Water temp fault s40

Post by Rob Stevens »

Try swapping the euc air temp pin with the water pin to totally discount a loom or sensor fault.
You'll have to talk to Alex to see if a fault can be repaired.
The 60 deg setting will be your default on sensor failure.
Motoroche
Posts: 4
Joined: Mon Feb 01, 2016 5:05 am
ECU Model: S40 Pro
Firmware Version: 79.02

Re: Water temp fault s40

Post by Motoroche »

Ok. Cheers for the help. So I should be seeing 5v at the water temp sensor plug then too like I am with the air temp sensor plug?
How do I get hold of Alex? Should I phone up dta?
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Water temp fault s40

Post by Rob Stevens »

With the sensor unplugged you should get 5v yes at the ecu, this is the 5v pull up.
yes phone up DTA if you can confirm the air and water test differently. Just try swapping the pins at the ecu to prove it onto the ecu.

It's a shame you can't assign an alternate unused input to this task if the ecu is faulty.
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: Water temp fault s40

Post by Alex DTA »

I'm actually on holiday this week, so phoning won't get me.
I'll look at this when I'm back in the office next week.
Motoroche
Posts: 4
Joined: Mon Feb 01, 2016 5:05 am
ECU Model: S40 Pro
Firmware Version: 79.02

Re: Water temp fault s40

Post by Motoroche »

I had the ecu tested by a local electronics engineer and he couldn't fault the water temp circuit. When he bench tested it he was getting the correct 5volts. It seems that the fault is at the ecu plug end. I plugged it in last night and it worked then today I unplugged it and bolted the ecu into the car and plugged it back in and it didn't work. Now when I wiggle the plug it looses water temp signal. Thanks very much for all your help guys. Just need to find the problem in the plug now.
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ignitionautosport
Posts: 577
Joined: Wed Jul 27, 2011 5:30 am
ECU Model: S80 Pro
Location: New Zealand
Contact:

Re: Water temp fault s40

Post by ignitionautosport »

Ah good stuff, was wondering if you were sending it or not :)
I can crimp a new terminal on for you if you like - or anyone who can crimp Motec/Link ECU terminals can do the same obviously.
| '94 GSR Lancer | '96 Toyota Carib 20V | '83 Toyota Starlet | www.ignitionautosport.co.nz |
Motoroche
Posts: 4
Joined: Mon Feb 01, 2016 5:05 am
ECU Model: S40 Pro
Firmware Version: 79.02

Re: Water temp fault s40

Post by Motoroche »

Ecu is all sorted now. I managed to track down some terminals and re crimp the water temp wire (24). Now the ecu is working very well. Cold start map is kicking in when the engine is cold and the fan comes on when the engine is hot.
Thanks very much to all that helped me sort out this problem, it's always tricky to find an intermittent fault.
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DTA Gareth
Posts: 37
Joined: Thu Feb 18, 2016 4:12 pm
ECU Model: No ECU

Re: Water temp fault s40

Post by DTA Gareth »

Glad you are sorted. Always worth a very close look over a loom
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ignitionautosport
Posts: 577
Joined: Wed Jul 27, 2011 5:30 am
ECU Model: S80 Pro
Location: New Zealand
Contact:

Re: Water temp fault s40

Post by ignitionautosport »

Excellent. :D
| '94 GSR Lancer | '96 Toyota Carib 20V | '83 Toyota Starlet | www.ignitionautosport.co.nz |
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