Cooling / Heating issue

[pimp'n]

Getting the following codes:

9537 - Engine Temperature too Low
P3081 - 008 - Implausible Signal
17701 - Map Controlled Engine Cooling Thermostat (F265): Short to Plus
P1293 - 001 - Upper Limit Exceeded
18613 - Performance Malfunction in Cooling System
P2181 - 008 - Implausible Signal
16804 - Catalyst System: Bank 1: Efficiency Below Threshold
P0420 - 002 - Lower Limit Exceeded - Intermittent

Looked at RossTech site and it would appear that my thermostat is shot as well as my temp sensor... both of which have been replaced in the last couple of years and the car has not been driven all that much? I have as yet not replaced the sensor on the lower rad tube / exit. If it was that sensor, could it be causing the codes on the thermo to be thrown as well? The minute I turn the car on the cooling fan comes on which I had thought was a function of the AC being on but not so much. Again is this indicative of a bad coolant sensor? Thanx for the input!

[pimp'n]

bump?

[old guy]

The code P2181 - Implausible Signal. 18613 - Performance Malfunction in Cooling System and 9537 - Implausible Signal.Temperature Too Low occur when the readings being monitored by the ECM fall outside of the expected range of the mapped cooling system. For example if the CTS in the lower radiator hose reads higher than the rear CTS where the coolant is at its hottest.

Once you get this code the ECM knows something is wrong so it does everything it can to protect the engine. Such as turn the cooling fan on as soon as you start your engine. A problem with either the upper or lower CTS can cause this code. but so can a faulty thermostat. For example, if during a cold start both the upper and lower CTS increase at the same rate that would indicate a failed thermostat. The ECM expects the rear CTS to get up to full operating temperature before the thermostat opens and the lower CTS starts to increase.

The mapped thermostat short to plus indicates that there is a problem with the thermostat heater. Check the wiring harness and plug for any broken/frayed wires.

A few questions: Is you block heating up? If so, how long does it take? What does your temperature gauge in the display indicate? Do you have any heat in the cabin? Answer these questions and we can figure out the next step in figuring this out.

[pimp'n]

Cheers! Block heat wise... I can drive it in CVT mode ensuring high RPMS and it warms to or close to 90 but under normal operation no. Temp gauge only just registers. There's no heat in the cabin BUT I think that's actually due to a motor flap issue and was next on my list of things to deal with. I have checked and flushed the heat exchanger and bled it again today as a matter of fact. No change there.

[old guy]

For starters it sounds like you have a defective thermostat. but let's confirm for sure. do you have software that will allow you to monitor the Measuring Blocks?

[pimp'n]

Yes I do.

[old guy]

OK. First disconnect the thermostat heater. I don't think yours is working because of the 17701 Short To Plus. But by disconnecting you will be running solely on the mechanical portion of the thermostat.

On your next cold start monitor measuring block 130. MB130 will give you the exiting temperature from the block (rear CTS) as well as the exiting temperature from the radiator (lower CTS). What you should see is the rear CTS temperature climbing steadily until the block is up to temperature. You can see this on MB130 as well as with the temperature gauge in the display.

During this same time the lower CTS temperature should not climb at all. It should remain cold. Once the coolant in the small loop (upper coolant hard pipe drop to thermostat and lower coolant return hard pipe) heats the thermostat up to operating temperature the thermostat will open and coolant will start to circulate through the radiator, lower radiator hose, and into the block through the thermostat. Once this happens the lower CTS reading will start to climb.

If you notice that both the rear CTS and lower CTS temperatures climb together that would indicate that the thermostat is opening prematurely and needs to be replace.

Edit: One other thing to check. On the cold start both of the CTS readings should be within a degree or two of each other. If not you have a bad sensor.

[pimp'n]

k. I will give this a go. Thank-you!