red lamp water flashing every second

[yanpat]

Hi ,

i have a 996 4S from 2003 and this morning i got a red signal for water temperature (flashing every second) and Needle of temperature of water i staying at zero.

I suspect the water sensor to be wrong. Do you have any idea where it is located ( picture will be welcome :)

or any idea of what i need to control.

thanks in advance

regards

[Loren]

:welcome:

It is on the bottom rear (outside) of the coolant tank.

The new part number is 997-641-503-00 Switch -- US MSRP $29.12

[logray]

If the needle is at zero though, wouldn't it be the water temp sensor in the coolant guide housing (right behind cats on right hand side of engine below the A/C pulley).

[phillipj]

Please make sure you are not losing coolant.. Logray and Loren are probably right about the switch.. I lost an engine because failed water pump.... Just erring on the side of caution...

[yanpat]

hi,

many thanks for your answers.

Loren, i looked and saw the sensor you are talking about. There are two wires on it. Do you know whether is it possible to put together those two wires in order to see if the default desappear.

Legray, what does it mind "right behind cats" sorry :)

phillipj, i'm not losing coolant , but i do not want to take risks. I use my bike :)

waiting for your answers

regards

[phillipj]

Good ... Just wanted to make sure... Hope you find a solution. I'm sure Loren and Logray will help you..

[Loren]

It is just a switch so opening and closing the connection should cause the light to go on and off.

[yanpat]

If the needle is at zero though, wouldn't it be the water temp sensor in the coolant guide housing (right behind cats on right hand side of engine below the A/C pulley).

Logray,

please could you give me more details about the location for the water temp sensor.

Could you provide me with a picture?

regards

[Richard Hamilton]

You can't bridge the wires on the temperature sensor. They are two separate outputs. One is connected to the DME, and the other to the gauge. The circuits are completed by the earth, so you could try earthing each wire, but I'm not sure what it will tell you.

Bridging the wires on the water level sensor would tell you if the level sensor is working, as Loren says.

Edited May 9, 2012 by Richard Hamilton

[1schoir]

"right behind cats" = directly behind the catalytic converters.

Regards, Maurice.

[yanpat]

Richard,Maurice,

many thanks for your council, that avoid my to do mystakes. :)

Do you have or could you provide me with a picture concerning the location of the

water temp sensor.

tomorrow ( for me right now it's 11 pm) i will test the lever water sensor by bridging wires, and will let you inform with the result.

regards

[JFP in PA]

You want number 2.......................

[logray]

Thanks JFP, beat me to it. :)

[yanpat]

hello,

here are some news.

I removed the air box and tested the sensor on the coolant tank. It is not on fault.

When i unplug it i get a different message saying" the level is to low" which disapear when i replug it.

So i have ordered a coolant temp sensor and will test.

When i removed the air box behind i found a connector which seems to be plug nowhere. here are few picture, am i right or not?????

or do you know where it is plug?

thanks

regards

[logray]

IIRC the connector at top of screen is for emissions diagnostics, it should remain unplugged.

[yanpat]

Logray,

many thanks for your answer, that makes me happy.

Have a good week end.

regards

[yanpat]

hello,

Today i have changed the coolant temp sensor, then i have plugged the PIWI cable and everything is clean. no more red signal and this is not a dream :)

Again i thank you for your help

regards

[logray]

Great work!

[questforbalance]

I need some help on this topic. I am getting the temperature fault code on the dash. The temperature sensor is at zero and does not move at all and I am getting the temperature fault on the dash. I changed the engine coolant temperature sensor, but still I get the same warning lights on the dash. I checked the DTCs and get: P0116, P0128, P0 430 and P0420. Some history: I recently changed the two front radiators, filled it and coolant level is good. I took car through a car wash one day before the warning light came on. Any idea how I can diagnose and fix this?

[JFP in PA]

I need some help on this topic. I am getting the temperature fault code on the dash. The temperature sensor is at zero and does not move at all and I am getting the temperature fault on the dash. I changed the engine coolant temperature sensor, but still I get the same warning lights on the dash. I checked the DTCs and get: P0116, P0128, P0 430 and P0420. Some history: I recently changed the two front radiators, filled it and coolant level is good. I took car through a car wash one day before the warning light came on. Any idea how I can diagnose and fix this?

Let's start with the year and model of the car please.................and some information about the scan tool used to read the posted codes as well.

And for reference purposes, an explanation of the flash rates for the temp light:

Covers all Carrera (996), GT3, TT / GT2 and Boxster (986) cars

Here is the long explanation from the service manual on the flashing coolant light.

"Four functions of the coolant warning light:

1. Engine coolant level too low -- light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high -- light is lit; pointer on the right

4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

[questforbalance]

Hello JFP,

My car is a 2002 Porsche Carrera C4S with 86,000 miles. I used Durametric to obtain the DTCs.

JFP,

Forgot to mention the car is a Tiptronic automatic transmission.

[JFP in PA]

You have a weird combination codes; two (0116 and 0128) point to the engine temp sensor and coolant thermostat signal plausibility problems (read the signal is either low in voltage or does not make sense), and the other two codes (0420 and 0430) say that the O2 sensors behind the three way cats on both banks are reading high voltage.

As this started after going through a car wash, I have to wonder if either something in the harness either got pulled loose or got wet in the process.

[Ahsai]

Refer to post #20 by JFP, which one of the four warnings is it? Does your temp gauge read normal temp (~180F) once the car is driven 10 miles or so? Can you use Durametric to log IAT, coolant temp, and all 4 oxygen sensor readings for a 10 mile drive starting from a cold engine? That should give us a much better picture of what's going on.

[questforbalance]

I worked on solving this problem today and so this is what I did:

I rechecked the new Engine Coolant Temperature sensor, inspected the wires and inspected the self adhesive tape I used to wrap the wires feeding the ECT sensor and the ECT (I wrapped everything up thoroughly). I then removed the B1 fuse from the fuse box just in case there was an air pocket left over from when I changed the front radiators three weeks ago. I opened the bleeder valve, cleared the DTC from the car's computer and bled the car all over again. I hooked up my hand held OBD2 reader and monitored the RPMs and engine coolant temperature sensor. After a few minutes the temperature sensor on the dash board starting working and indicating the coolant temperature. I compared the result with my hand held OBD2 reader. I spent a good 30-minutes reving the car and trying to bleed the coolant system. The car did not need any more coolant. I drove the car for about five miles and no codes returned, no flashing lights and the temperature gauge was working properly.

My theory is that the car wash may have shorted the ECT somehow and caused the coolant system to malfunction. Everything seems ok for now. Hopefully it stays this way. Thanks for everyone's help and I hope this posting helps others with the same problem.

[Ahsai]

Glad you get it sorted out. Sounds like a flaky connection.