Ecu Temperature - Resistance Values

[Powers 13]

I have searched the forum for ages as I can remember someone posting up a table of the ecu temperatures and the associated resistance values.

Did anyone save the post in their favourites?

Cheers

[KRISKARRERA 2 1 Cars]

Does one mean the resistances of the Coolant Temperature sensor?

[Powers 13]

No, the ECU temperature sensor thanks.

It was a table of the water temperature against resistance. Ideal for checking to see if you have a faulty or wrong sensor.

Edited May 3, 2007 by Powers

[pug_ham 242 3 Cars]

ECU temp sensor is the coolant temp sensor. (blue plug / sensor)

 

Graham.

[KRISKARRERA 2 1 Cars]

I've got them in Haynes, I'll post em up later.

 

I should say though that they wont match - I tested mine and the resistances were slightly different to Haynes' figures so I bought a new sensor from Pug only to discover the new sensor had same resistances as the old sensor!

[Powers 13]

Ah, it would be great if you could post them up.

Also it would be good to know what tollerances to use.

[Guest larson]

http://www.bosch-motorsport.de/pdf/sensors...ure/NTC_M12.pdf

 

Bosch CLT Sensor 0 280 130 026

[PumaRacing 1]

I have searched the forum for ages as I can remember someone posting up a table of the ecu temperatures and the associated resistance values.

Did anyone save the post in their favourites?

Cheers

 

They all work the same way and generally run from about 3000 ohms cold (room temp) to 300 ohms hot (90/100c). The exact values aren't that critical as long as the resistance drops steadily as the temperature increases. If you check it both cold and in a pan of boiling water you'll find out if there's a major issue. Sometimes, very rarely, they develop a fault where they go open circuit at one particular temperature and then work again above and below that.

 

I remember a colleague trying to trace a fault in a BMW where it would start from cold, run for a while and then stop but if you left it for a few minutes it would start again and then be ok for the rest of the day. Kept him amused for ages until he finally found that the temperature sensor gave the right reading cold, suddenly went open circuit as the coolant warmed up and then heat soak from the engine took it past that point and it was ok again. Very hard to spot and very rare. Normally they're either fine or just fail completely.

[petert 554]

This may be of use, although it's the thermistor for the thermo fans, not the ECU. Some are NTC, some are PTC.

[Powers 13]

Thanks for the help lads and especially to Larson that PDF was exactly what i was after.

After testing the ECU temp sensor provided by my local motor factors (Non Bosch unit) it is different to a Bosch unit (Supplied by Peugeot) by 400 ohms @ 17degrees and 250 ohms @ 75 degrees. The Bosch values are the lower ones. Hence my engine would be slightly over fueling, obviously reducing efficiency. My 405 Sri should now run that tiny bit better.

 

 

They all work the same way and generally run from about 3000 ohms cold (room temp) to 300 ohms hot (90/100c). The exact values aren't that critical as long as the resistance drops steadily as the temperature increases. If you check it both cold and in a pan of boiling water you'll find out if there's a major issue. Sometimes, very rarely, they develop a fault where they go open circuit at one particular temperature and then work again above and below that.

 

I remember a colleague trying to trace a fault in a BMW where it would start from cold, run for a while and then stop but if you left it for a few minutes it would start again and then be ok for the rest of the day. Kept him amused for ages until he finally found that the temperature sensor gave the right reading cold, suddenly went open circuit as the coolant warmed up and then heat soak from the engine took it past that point and it was ok again. Very hard to spot and very rare. Normally they're either fine or just fail completely.

 

This is the exact problem the 405 had when I bought the car; luckily the Peugeot engine management fitted isnt that complex so it was one of the first things I changed.

Thanks again.

[taylorspug 7]

If you want all the resistance values, there is THIS article on the main site with a great deal of them.

Edited May 5, 2007 by taylorspug