hally

Hi,
So far I have gleaned from various threads that the DME temp sensor:
- is located near / under throttle body and measures coolant temperature.
- is a NTC II sensor that generates a resistance inversely proportional to the coolant temperature
(continued.. accidently posted before I had finished)

hally

continued..
- effects cold start behaviour, more fuel is added when coolant is cold.

Does anyone know if this sensor has a role in the continuous running of the engine (once the engine is started / cold start behaviour is complete.)

also what tool / size have people used to remove it (maybe a long socket would work), was too narrow in there to use a spanner.

thanks

Jaak Lepson

Hally ... the temperature sensor that is usually faulty is the one INSIDE the AFM, just like mine!!! This measures in incoming air flow temperature. The one on the block generally does not fail, or cause the problem you posted earlier.

Check under map/maf????? post from last week and in it I list what the resistance readings in OHMS you should read from terminal 1 and 4 on the AFM socket. When it fails, it defaults to 20 degree Celsius readings.

Both the AFM and Temperature sensor is NFG since I got the car. I have one coming from Scott.

This may be the excuse you need to upgrade!

Jaak Lepson

MHT

the coolant temp. sensor does indeed play a very important role in determining the amount of fuel injected at all times. If the sensor goes open the ECU interprets that as an engine temp. of approx. -30 degrees and dumps fuel, even if the engine is actually hot. The sensor can be removed with a deep 19mm socket. I have seen problems with the pigtail connector to the sensor. It might be worth your while to solder in a new connector when you replace the sensor.

Mark

Asarus

Would someone have a picture of this sensor and its location ?

awilson40

Right on MHT, The connector is a standard bosch fuel injector connector. Lots of heat there and the wires in mine were shorted causing it to run rough when cold. I replaced it and cold issues were gone. If you remove the connection on a warm ,running engine it will belch black smoke and stall.

RPG951S

Whoa, are we all talking about the same thing?

The Engine Coolant Temp Sensor is located in the block, just right and below the #1 spark plug. Part # is 94460612500.
I had to remove the [stock] upper air filter cover and IC to TB pipe to get to it. It has a blue fuel injector style connector.

BTW- changing mine made zero difference with my cold start problem. Just the same, since it is so inexpensive, I'd change it regardless.

Here's a pic of Rob Langley's beautiful motor with him installing it:

Pic of Rob's Engine/Temp Sensor install

Waterguy

There are two identical temperature sensors on the 951; one for the temperature gauge and one (NTC II) for the DME. The one illustrated is for the gauge. I don't have a picture of the NTC II sensor, but on mine it it located just below the intake manifold at the front of the engine, to the left of the AFM. It has a round black single-wire connection on it (on mine at least.) You may indeed have to pull the airbox and intercooler pupe to access it.

awilson40

Waterguy...I think that is the NTC II sensor. I just finished replacing the connector at the sensor and checking continuity at the DME connector.
the single wire sensor is the gauge...the 2 wire connector sensor is the NTC II

blitz951

My car sometimes doesnt start after it is driven. It cranks over but it gets no spark. I have gone through everything and the dme and relay is ok so could this sensor give these sympoms. Is this sensor to the dme a possibility that is causing this problem? Thanks.

Waterguy

My bad. I just double checked and you are right. I wil have to check my NTC II connector. Thanks.

hally

There seems to be some confusion around over the various temperature sensors in the 951 and what role they play, me included.
I am talking about part number 606 125 00, but its not on the block, it is attached to a pipe off the coolant tank which runs under the throttle body.
It feeds pin 13 on the DME as waterguy I think explained in another thead.

Thanks everyone, hopefully this will help me diagnose / eliminate this sensor as my problem (thanks for the socket size MHT also), which is:
when cruising along, DME suddenly goes into open loop, which I can see from the o2 sensor digital display. I am thinking that a bad TPS could also cause this?

Is there a part number for the connector, or just a generic spark plug style connector will do.

Jaak what part number is the temp sensor in the AFM, does this sensor also connect to DME or is its output incorporated into the load voltage output from the AFM?

I wonder if someone out there has a document describing every sensor on the 951 and what role / effects it has, especially if misbehaving, that would be gold.

cheers

Danno

"There seems to be some confusion around over the various temperature sensors in the 951 and what role they play, me included.
I am talking about part number 606 125 00, but its not on the block, it is attached to a pipe off the coolant tank which runs under the throttle body. It feeds pin 13 on the DME as waterguy I think explained in another thead. "

Uh no, that part on the water-pipe is the turbo water-pump sensor. It should ONLY hook up to the water-pump relay and has nothing to do with the DME or engine-temp or air-temp sensors.

The air-temp sensor is part of the AFM and is internal to it. The signal comes out of the same harness connector as teh air-flow signal and runs to the DME. The air-temp sensor serves two purposes, compensation for air-density and cold-start enrichment. Of these two functions, the compensation for air-density is minor given the typical operating ranges these cars are under.

A more significant function is cold-start enrichment. This starts first with the engine-temp coolant sensor. If it indicates the engine is cold, the DME references the air-temp sensor to determine how much additional fuel to add for cold-start enrichment.

hally

thanks danno,
No wonder I got no change when I disconnected the turbo-water pump sensor. .
I'll try again to locate the DME temp sensor, at location described by waterguy.

Tony

flash back….what is this sensor and part number…..thnx

87

Temp sensor…single wire..circled in red..




thats not my engine (I wish)…just for reference.