Code 128 : Water sensor

[Comet]

Can any body shed some light on what a code 128 : water sensor means? The water temp on the display went up to 110 degrees a couple of times but both fans kicked in and reduced the temp accordingly although the first fan didnt kick in till 103ish - sounds far too high to me! Also didnt get any steam from the bonnet which is what i was expecting so could it just be a faulty sensor? or something more major? (hopefully not) Any ideas anyone???

[shep1001]

Two temp sensors are under the air box in the block (one for the ECU temp readout for the fans the other for the dash) - They measure the water temperature! fans should kick in about 92 & 98 degrees. The sensor may be duff, if you have the ECU software plug it in and see what temp this shows against the dash. Cheap to replace but the sensors are different, the dodgy one will be to the rear of the block. If you unplug the sensor the fans should run by default, simulating the 128 code fault.

Shep

Edited by shep1001 on Sunday 26th February 21:14

[Comet]

Thanks Shep! Looks like i will be taking a trip to the garage shortly

[Druid]

Don't leave it too long Martin. Make the assumption the temps are accurate and get it sorted. The rear temp sensor is read by the ecu and is the one that switches the fans on. The front sensor just feeds the dash indication which is the display you see, of course it could be the real temp of the coolant.

It's always worth pulling the connections on the sensors and cleaning them as they corrode and then report over temps.

As shep says if you pull the connections on the rear sensor then both fans should run as default.

Please let us know what the fault is when it's solved.

[Comet]

Had both the sensors changed and still the fault code 128 comes up with the temperature going 100 degrees upwards. I have now been told that the reason for the code now flashing up is due to a TVR design fault with the radiator position. With the radiator in the Sagaris laid horizontal and not being set at an angle the pump is not powerful enough to circulate the water and therefore gives a high reading warning. To overcome this i should (when sat in traffic) lift the revs above idol and this would help kick the pump in. My choices are now to elevate the radiator so it is raised or secondly install a more powerful pump which you need to take the engine out!

Has anyone come across this before and found a solution as i cant believe i have to live with this sensor flashing up every time i hit traffic and sit with my foot on the accelator to enable the water pump to circulate.

As you can guess i am not mechanically minded and wonder if anyone has had a similar problem?

[RedSpike66]

I've not heard of a lot of Sags having this issue generally, perhaps you need to make sure your coolant level is full and no air in system. Jack front of car up whilst running it up to temp to get air out. There's also bleed screws on the pipes before/after the rad.

[cinquecento]

Sunny days of over 35deg C don't even effect the water temp .. I haven't seen anything over 96deg C .. so I'm not too sure abt this particular "design fault"!!

[shep1001]

Comet said:

Had both the sensors changed and still the fault code 128 comes up with the temperature going 100 degrees upwards. I have now been told that the reason for the code now flashing up is due to a TVR design fault with the radiator position. With the radiator in the Sagaris laid horizontal and not being set at an angle the pump is not powerful enough to circulate the water and therefore gives a high reading warning. To overcome this i should (when sat in traffic) lift the revs above idol and this would help kick the pump in. My choices are now to elevate the radiator so it is raised or secondly install a more powerful pump which you need to take the engine out!

Has anyone come across this before and found a solution as i cant believe i have to live with this sensor flashing up every time i hit traffic and sit with my foot on the accelator to enable the water pump to circulate.

As you can guess i am not mechanically minded and wonder if anyone has had a similar problem?

I would suggest you take it back to the garage that did the work and ask them to look at it again or go somewhere else for a second opinion! Never heard of this before I would suggest either the new sensor is faulty which can happen or the system is leaking so its not pressurised or has an air lock.

[spercy]

I had this come up on my T350, but only in torrential rain. I was told it was water ingress to the electrics, which was sorted out by re-sealing something. Sorry i can't be more specific but it was all done for me free of charge under the Str8six warranty that the car came with