Re: help with coolant temp sensor?

[Chris Lemon <br00206@binghamton.edu>]

On 14 Nov 1996 14:55:14 -0700 Creel, Kenneth E wrote:

>I'm getting a fault code on my '90 90q20V (99k miles) that says that 
>the coolant temp sensor is bad.  I looked through the Bentley and I'm 
>a bit confused as to the location of this sensor.  One diagram points 
>me to a location between the engine and firewall, another to a point 
>the lower part of the engine where the coolant hose enters (beneath 
>the fuel injectors).
>a)where is this part?

The ECU temp sensor is mounted into a flange on the intake side of the head.
The multi-function temp sensor is also mounted into this same flange.  ECU
temp sensor is 2 pin, however.  

>b)is this the same sensor that feeds the dash gauge and the climate 
>control (on diagnostic channel 6) ?

No.

>c)the temp gauge appears to behave as if only the thermostat is bad, i.
>e., normal temps in the city, cool at high speeds - so my inclination 
>is just to replace the thermostat.

Your thermostat is either stuck open or it is opening too soon; temp should
remain fairly stable regardless of driving conditions.  How cool are you
getting on the gauge?

>d)could this have anything to do with my cold-starting problems?

Yes...if the sensor is actually bad.  I (and at least one other list member)
have this same problem and have not been able to solve it.  I have replaced
the ECU sensor and the wiring checks out (at least at the time when I check
it) and I _still_ get that damn check light every once in a while (code dump
always says the ECU temp sensor and or wiring is bad).  There might be an
intermittent break in the circuit that appears only when driving but who
knows...

==========================================    
Chris Lemon          
br00206@binghamton.edu         
http://www.geocities.com/CollegePark/1710/  
==========================================