free hit
counters
Coolant Temperature Sensor - Code 15 - Engine/Ancilliaries - The Lotus Forums Jump to content
Sign in to follow this  
Mysterae

Coolant Temperature Sensor - Code 15

Recommended Posts

There is a simillar thread to my questions, but thought I would start another rather than hijack the other one!

I have a Code 15 error code - "Coolant Temperature Sensor Circuit - Low". the Freescan manual states "Code 15 will be set if: signal voltage indicates a coolant temperature above -44C. Engine running for longer than 1 min".

The Coolant Temp reading from Freescan itself indicates a temperature of whatever the Start Temp is at (say 30C) then shoots up to 85C (engine running) and doesn't budge. Turn off the ignition and check again, the temperature goes back down to 30C ish again. There is no gradual rise or drop in the reading.

Safe to say the coolant temperature sensor is knackered? Sat here looking through the Freescan manual tells me I should have logged a coolant sensor voltage doh!

I can see the sensor in the parts manual, but what I think it is looks nothing like it! I'm in the area of the inlet manifold.

Anyone got any pointers on changing it?

Share this post


Link to post
Share on other sites
Upgrade today to remove Google ads and support TLF.

It's well hidden, sitting under the inlet manifold. I took the cover off the inlet manifold for better access, but you may not need to do this if you have a good mirror and plenty of lighting.

Sometimes it's a simple matter of cleaning and tightening the electric connector on it. I've replaced mine and it wasn't too hard. I don't think I lost too much coolant in the process (you just have to be quick putting the new one in) :thumbup:

I recall having the same doubts about the shape/size of the sensor, too, but don't worry, it's probably the only sensor in that area.

Good luck!

Cheers.

Ian.

P.S. You'll need a 3/4" deep socket and an extension bar (You may have trouble getting a spanner in there)

Edited by Qavion

Share this post


Link to post
Share on other sites

Thanks for the reply Ian.

You mentioned access, it is a bit cramped and dark in there! I was thinking of removing the boot floor to get access that way (a dab hand at that now!) but was removing the inlet cover easier? Did you have to replace any gaskets?

I've ordered a new sensor anyway, they aren't that expensive.

Share this post


Link to post
Share on other sites

Do you mean the gaskets for the inlet cover.. or the sensor? Thankfully, my inlet cover gasket was unsealed and seemed to be in good condition. I can't recall if I needed a gasket or not for the sensor (If there is a gasket or o-ring, it's probably included in the sensor kit anyway). I don't think my old sensor was sealed ... and the surface was clean, so I may not have used sealant on the old one (can't quite remember).

The boot floor is really overkill. I think I only removed the inlet cover for better visibility and to make sure I wasn't damaging something- & I think I was worried that I couldn't relocate the new sensor fast enough. I lost about 250~300ml of fluid (half a pint?). By that time, I think the fluid stopped coming out anyway.

If you have the right tools and long enough arms :thumbup:, it really shouldn't be difficult.

Cheers.

Ian.

Share this post


Link to post
Share on other sites

I do have long arms but still think it will be difficult to access! I can't even see the sensor!

I did mean the gasket on the inlet cover. Knowing my luck I would need to replace it if I touched it at all.

I can remove the boot floor pretty quickly, and I think sitting on the gearbox will make the job a bit easier. I need to check the translocator on the gearbox and remove header tanks to spruce them up anyway.

Unfortunately the sensor won't get here in time for the weekend so it's going to be a job for during the week or next weekend. I'll let you know how I get on.

Cheers,

Alan

Share this post


Link to post
Share on other sites

"I do have long arms but still think it will be difficult to access! I can't even see the sensor!

"

I think it's just aft of the oil filter, somewhere around the mechanical chargecooler pump (if you still have one), so it's not right at the back of the engine (that's why I'm not sure if taking the boot floor out would be any help).

Sounds like you have plenty to do under the floor though (Last time I took the boot floor up, I kept finding things to do... 3 months later, the car was back on the road :yes: (new gearbox translator linkages, new gearbox mount, new turbo, new exhaust.....)

Good luck!

Cheers.

Ian.

Share this post


Link to post
Share on other sites

I finally managed to get some time working on the Esprit to replace the coolant temperature sensor - and it fixed my code 15!

I did eventually take the boot floor out to give me more access to see the sensor. Removing the air filter box was more helpful, I could get my arm in to put the spanner on. I used a 'dumpy' ratchet ring spanner (from Halfords) and it made the job a lot easier. It needed a few knocks from a hammer to start.

Freescan was showing a much better gradual temperature change.

I just need to get on to the other jobs now...

Share this post


Link to post
Share on other sites

Thanks for the feedback, Alan. Great to hear you had success :D

Cheers.

Ian.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  


×