TEMP GUAGE NEEDLE LEFT .RAPID RED LIGHT

[BIG BEAR]

SCANNER READS ENGINE TEMPS CORRECT AND FANS COME ON AT 212 F . THE GUAGE DOES NOT MOVE AT ALL LIKE ALL GUAGE NEEDLES DO WHEN YOU GO KEY ON . RAPID RED WARNING  LIGHT ON TEMP GUAGE. DOES ECM GET A SIGNAL FROM A SEPARATE SENDER  ? OR DO I HAVE A GUAGE PROBLEM ?

[JFP in PA]

Welcome to RennTech 

 

First of all, posting in all caps is considered rude by many posters, and is completely unnecessary.

 

Most likely, your problem is a filled temperature sensor on the engine, but I would not be driving the car until a shop can confirm and repair the issue.  These engines are very sensitive to damage caused by overt heating, and with an inoperative dash display you really don’t know where the actual temp is.

[BIG BEAR]

Sorry for the caps , was frustrated and in a hurry . What is a “filled temperature sensor “ and how does the ECM know the temp. so as to tell the scanner live readings that I see and tell the fans to come on at 212 F ? Thanks for your help . 

[JFP in PA]

1 hour ago, BIG BEAR said:

Sorry for the caps , was frustrated and in a hurry . What is a “filled temperature sensor “ and how does the ECM know the temp. so as to tell the scanner live readings that I see and tell the fans to come on at 212 F ? Thanks for your help . 

 

Sorry for the typo, it should have read "fluid temperature sensor"  The DME monitor's the sensor electrically and converts that signal into temperature; when the limit is reached in the DME's softweare, the fans switch on until the temperature drops.

[BIG BEAR]

Hello

So the DME is seeing a functioning fluid temp sensor  ?  Also if I disconnect the coolant temp sensor it throws a check engine light with a coolant sensor code . So this  should say the sensor is good ?  Whats worse is the OE wire diagram of the                                     “ guage  cluster “  shows no temp guage what so ever and no communication circuits from any ECMs to a temp guage . As if it dose not exist . Any ideas about that .

 

Thanks for your time .  

[JFP in PA]

2 hours ago, BIG BEAR said:

Hello

So the DME is seeing a functioning fluid temp sensor  ?  Also if I disconnect the coolant temp sensor it throws a check engine light with a coolant sensor code . So this  should say the sensor is good ?  Whats worse is the OE wire diagram of the                                     “ guage  cluster “  shows no temp guage what so ever and no communication circuits from any ECMs to a temp guage . As if it dose not exist . Any ideas about that .

 

Thanks for your time .  

 

The DME gets the single from the temperature sensor and communicates with the cluster via CAN Bus.  Disconnecting the temp sensor throws a "no sensor" code, but does not mean that the sensor is good by default.  The coolant temp sensor can be read live (actual temp values) using a Porsche scan tool.  If suspect bad, replace it, it is not that expensive or difficult.