Well, here is one that I just can't figure....great car, but this problem is driving me crazy (wife too ...she is afraid to drive it now). I have been swapping sensors with no results. Here is the problem...the engine will start and run great cold. When it warms up and the ECR switches to closed-loop mode, the IAC valve takes the RPMs up and down between 500 and 2500 RPMs. If the car is switched off during this time it will not start until the engine cools back to warmup operating mode. I found that a previous service job had misrouted the vac line that goes to the EGR ... it had touched the exaust tube and melted shut. The vac line is now replaced, but the surge and hot-start problem is still there. Getting diag code 123 (coolant temp sensor) during the whole time...sensor was replaced and wiring to the series ground and to the ECU was checked ok. Anyone ever seen anything like this? Tom Haywood

I just had the exact same thing happen to my '96 960. Symptoms were surging idle, check engine light, which was because of bad CTS, and then hard starting, poor idle, and poor low rpm performance. I replaced the CTS and that resolved all the issues.

Well if you are still getting the CTS code then that must be rectified before anything else.

How did you trace and verify the entire circuit? That lead passes through several tie point and junctions. Any one of them is suspect. Also suspect is the actual pin contact where it enters the ECU.

To rule this out, lets find the warm spec for resistance on that CTS, go buy that resistor at Radio Hack and temporarily install it in place of the CTS signal. Fixed?

I errr, "happen to have" the full and complete schematics for the 95 960 at home. I can get into this deepr about 10 hours from now if you need it.

T.Tom...Yep, I realize that you are right about looking much closer at the coolant sensor. I've been using a 1K pot (variable resistor) and still the 123 code keeps poping up. I sure would like to buy a copy of the schematics...where did you buy it? (email me?) Thanks for the input. Tom Haywood SouthVista@aol.com