Chrysler Repair: engine stall after car is hot, chrysler sebring, temperature sensors


Question
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Followup To
Question - 1996 chrysler sebring (2.5 engine w/ac) no read out on computer sill runs and dies after 5 menutes.new tune up last month plugs,wires .i need help? this car has arlarm system with autostart also.
after the car runs for 15 minite it will stall out sound like no fuel. had it tune up last month never did it untill tune up.only will stall out when car warms up.1996 chrysler sebring convert with 155000 miles.
Answer -
Hello Lee,
It may well be that one of the temperature sensors on the engine is not working properly. To check that out, the most useful thing to do would be to try to get the fault codes that are likely stored in the engine controller memory to readout. Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). Then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for several of the engines and we can look up the possibilities of what is wrong based upon what fault codes you show. When you write back tell me which engine and transmission you have in the car.
There is also an essay on fault codes at the site:
http://www.allpar.com/fix/codes.html
which gives the meaning of the code numbers. But then you need to get specific info for what exactly might be the diagnostic tests or parts to replace to complete the repair. And that is where I can hopefully be of help to you.
Roland  

Answer
Hi Lee,
One further thought: the stalling out when the engine gets warm could also be the result of the four oxygen sensors being brought into play at the point when the engine has been perceived (by the coolant temp sensor) to be warm enough to enter into "closed loop" operation. That set up means that the O2 sensors' data are used to adjust the fuel mixture. If one or more of the sensors were either not working well or not connected well that would cause an incorrect fuel/air mixture which is what you believe is happening. In most cases a "21" code for the O2 sensor being out of range should be expressed, but that is not always the case. There are quite a few different tests to perform to nail down which sensor signal is bad and why, so I can't easily give you something to do. It would help if you had more sophisticated code reader to plug in for the reading than the check engine light which only says the sensor is bad (code 21) because there are actually about 15 different sub-codes and 4 sensors (two on each bank of cylinders) on the 2.5 V-6 engine. It is too costly to take a chance and replace all 4 sensors, so a better readout of the controller is probably what is called for if the temp sensors themselves check out to be o.k.
Roland





Hi Lee,
By "no codes" do you mean the check engine light didn't begin to flash at all or do you mean you only got the code 55?
As to what to do, I would recommend that you check the resistance of the engine coolant temp sensor and the intake air temp sensor. The ECT is located right next to the filler pipe for the cooling system (the one with the removable "radiator cap"). If you have an ohmmeter you can verify that it is working by measureing the resistance between its two prongs(after removing the plug by lifting the tap and pulling). When the engine is cold it should read 7,000 to 13,000 ohms. When it is warmed up (when the engine "dies") it should read 700 to 1,000 ohms. Remember to reattach the plug after the measurements. Similar values when cold and warm will be found for the IAT sensor which is located on the side of the intake manifold (near the MAP sensor); you will know you have found the IAT if its two wires are colored black/light blue, and black/red. You may find that the tune-up person forgot to attach the plug to the engine coolant senaor (ECT) because the timing is often verified with its plug disconnected. If both those sensors and their plugs prove to be o.k. and you can't get anyother codes, I suggerst that you go back to the tune-up shop and tell them about the problem and that it started right after the tune up. Maybe they will recognize something they did wrong.
Let me know how this problem is resolved.
Roland