HELP! Engine service indicator!

[BuzziBi]

First excuse me my bad english
Got a 2.3 L and the service indicator (light) komes on when the engine is hot (normal temp.).
When the engine reatsh normal temp. and the engine fan starts, it won't stop again. The voltagemeter shows a fall in voltage when the fan starts and the servicelamp comes on.
If I turn ignition of and starts imedeatly it's all ok until next time the fan starts. Eks. when I stops fore a trafficlight.
Any sugestions?

[LMP]

please describe what car you have, year model, etc......ahh OK, got it from your profile, 1996 Transport.
radiator fans require lots of current so some voltage drop is expected, depending where the voltage sample is taken, specially at low rpm.
NOtice the 2.3 in the Transport is unheard of in America so probably expect european users to provide info on this matter. I know from european forums that the 2.3 is prone to head gasket failure and this would induce overheating. I hope though there is a more benign explanation for your problems.

[BuzziBi]

[quote=LMP]please describe what car you have, year model, etc......ahh OK, got it from your profile, 1996 Transport.
quote]
The engine is not overheating, it runs on normal temp. And the fan ciks in as normal. It just won't stop again
Tryed to change the ECM/PCM but same error. Have checked grounding points, but I can not find any reason fore the voltage drop.
I believe this problem can occure on any model or any engine?

[LMP]

..about voltage drop: I have experienced several occurrences of alternator failures...with my 3.8, but as you say... this is not related to engine size...
Once the voltage regulator failed, the other time, one diode in the 6-pack block failed, both are built inside the alternator. IN both cases I changed the component only. One failed diode means the alternator will still be able to feed 12V at low loads, but not at high amp loads. An accurate voltage measurement with varying loads might help diagnose the problem.
It is possible the voltage drop when the fan starts could impair the logic levels of the computer so it is unable to make further changes once the fan has started. One simple test: I'd jump the battery with another car running at idle to maintain voltage to see if the fan would recover normal operation....

[BuzziBi]

[quote=LMP]..about voltage drop: I have ......quote]

Thanks fore troeing good ideas
I measured the voltage to day (changing oil and filter) and the alternator is feading 14,8 Volts (is'nt that high?) but I havent tested vith different loads. I'm going to try that tomorrow.
I tryed disconecting the idle air control IAC, and found that the high idle disappeared. suspect that this one is "OK NOT"
But still the problem that coolant fan wont stop when it first have started.
Just have to continu troubleshooting

[LMP]

Originally Posted by BuzziBi

...the alternator is feeding 14,8 Volts (is'nt that high?)

..well, I would expect voltage around 14.5, 14.8 being a little high maybe but not excessive; I noticed the voltage starts high and drops somewhat after a few minutes, probably heat sensitivity of the controller electronics, and that effect is amplified in cold temperature, running well above 15 right after starting...we are experiencing extremes of temperatures nearing -40 this week....at -40 it does not matter if it is °C or °F... ..but as I do not really need going out, I will not make any tests this time.....

[BuzziBi]

Thanks!
Snow and ice today and -8 C. No wether for troubleshooting outdoor!
Staying i house and trying to keep warm. Thanking God for my warm girlfriend! LOL

[Jeffrv]

A few questions, does your van have air conditioning? What style of Assembly Line data Connector does it have, and how many wires are present? When the fan comes on, how long does it keep running, and does it only come on after you have stopped in traffic?
Jeff

[BuzziBi]

Originally Posted by Jeffrv

A few questions, does your van have air conditioning? What style of Assembly Line data Connector does it have, and how many wires are present? When the fan comes on, how long does it keep running, and does it only come on after you have stopped in traffic?
Jeff

Dont know about style of Assembly Line data Connector. Cant find this out in my Haynes Repair Manual (Who by the way dos not cover the 2.3 engine )But it have 12 posible links (6 up and 6 down on the conector) but only 3 of them in use.
The nr 6 nr 10 and nr 12. Where nr 1 is upper left corner. Was this understandably?
And I dont have air conditioning. We live in a cold country
It looks like the fan could run forever! But still while car in motion I turn ignition of and back on, this resets error and stops the fan! The problem only occurs when engine is hot and stop driving (engine still running) gues the driving is enough to cool down the radiator and that the fan dosent run while driving in vinter temperature.
A thought: Can the coolant temp sensor cause the problem?
Is the coolant temp sensor feading the IAC valve through the ECM/PCM causing the problem with high idle?

[Jeffrv]

Ok, you have the OBD 1 style ALDL connector, with OBD 2 style wiring, like some 94 and 95 Transpsorts here, so you can't "flash" codes out of it. I was considering that you had a faulty high pressure A/C switch that was triggering the fan to come on, but with no A/C, thta's not the problem. How soon after you start the van does the the fan want to come on? Your idea that the engine coolant temp sensor is faulty may be right. The PCM takes info from sebveral sensors, including ECT, a and determines the appropraite output, ie spark, fuel, IAC etc to run the engine. If the PCM detects an abnormally high or low signal, , dedected for a period of time( usually around 10 to 20 minutes continuously) it can illuminate the MIL light, as well as set defaults, like turn a fan on continuously. This could be the result of a bad ECT sensor, or the wiring harness between the ECT and the PCM is broken or shorted, or a pin not making connection at a connector. Has there been any work done recently on the van where a connector was taken apart?
Jeff

[BuzziBi]

Originally Posted by Jeffrv

Ok, you have the ........apart?
Jeff

Looks like the fan starts as it should when the engine reatch normal temp and not driving.
No work done that shoud caouse this. It seam'es to me that it has escalated over time getting worse and worse.

[BuzziBi]

Could not resist temptation. Had to make a signature LOL

[Jeffrv]

Hard to guess without running a check on the codes the computer is storing, but I still think it is in the ECT circuit. By having the fan work properly whuile not driving it, the basic circuit is proven ok, but it acts up when you drive. I'm not familiar with the 2.3l engine, but most front wheel drives use some sort of brace to keep the engine from rocking back and forth, a lot, is there one on yours, and is it keeping the engine in place when you load and unload torque on it by driving?
Also, unplug the connector at the temp sensor, and measure the voltage there. I suspect this engine will be similar to the V6 and should have 5V across it when you turn the ignition on ( don't start the engine). Then follow the wiring harness and wiggle it and all connections along the way to see if the voltage drops, indicating a short or open circuit.
Jeff

[BuzziBi]

SORRY!
I forgot to publish what was the error after I had finished the repairs. Has now received a new error but I would like to publish the reason for the last repair!
The fault was a cracked hose that was connected to the intake manifoild (ca. dim. 1/2" thick and 3" long).
I'm unsure of what this does because I do not have the engineering manual for my engine, 2.3 L. There is a long, flat sensor? (It looks like a heater) inside the hose. The crack was not visible because the hose is behind manifoild! I suspect that the sensor covering the crack, made the error not constant.
Anyway, now I am going out to measure the engine coolant temp. sensor!
Symptoms: hard to start when hot, enging service lamp ligts up after 30 sek. computer goes to backup solution, and the radiator coolant fan is running constant again!