1991 Ford Tempo - SES Light

(EASY) Take the car to the local parts store and ask them to run a diagnostic test to give you the trouble codes. Normally, they will do this for free with the hope you buy the parts from their store.. and not off the Interwebs.

(Slightly less EASY) If it is a OBDII Connection, you can ground pin one (jumper from pin 0 to pin 1) on the Connection under the dash on the driver side(usually right about at the left knee), and watch the blinking "Check Engine Soon" light... If i remember right, It will blink two or three times, then start blinking the trouble codes, then blink another two or three times when finished. You will need to ground the pin with the ignition off, then when grounded turn the Ignition on(Do NOT start the engine). Get yourself a repair manual for the car, it will have this procedure in greater detail, and list all the possible codes, with their definition.

Thanks for the suggestions. However, when my dad took the car to our local AutoZone, theytold him that the car didn't have a connector they could plug into.

Any suggestions on a good repairbook for the car? The Chilton's book I just bought doesn't even mention the light!

Bummer no connector in the engine comp...then you will have to take RVZ717's good answer slightly less than easy and use the connector under the dash above your knee. However, do not worry too much, since the light is steady those are benign problems or just time for some major service. When check engine lights blink all the time, that usually indicates more serious problems.

Maybe a Haynes manual?? I'm really surprised the Chilton's doesn't have anything on the OBDII diagnostics.

check your gastank cap. Sometimes is something very simple. If it is defective it will give a wrong reading.

If that does not help, place a business card over it, and dont worry. Most garages themselfs do not know the answere and replace parts one at a time until they hit the target.

There are not to many good mechanics left, who think of the unthinkable.

Anita

Unfortunately, that "repacing one part at a time until it is fixed" technique is all too common these days! I will see if I can find someone who has a Haynes manual and check if the info on the SES light is in there before I buy it.

Thanks to everybody for all the comments and suggestions! I'll be sure to report back if/when I get this fixed.

I had an old Haynes manual for a mid 90's Chevy pickup. It did have the trouble code section, and diagnosis information. Really helps if you know which part to change before tearing into something.

Pick up your phone, and start calling other auto parts stores and ask them the same question. Any of the better OBD II readers will have adaptors that allow reading pre OBD II computers. There was a diagnostic connector on that car when it left the factory. There was a grey, or black plastic plug with a separate wire connector right next to it. The main connector plug had about 6 spaces in it for 1/4" spade terminals, although only 2 to 4 were actually fitted with wires. The second connector had a single wire in it. It was usually taped to the main connector with black masking tape. One corner of the main connector was made with a 45* angle. Look under the hood on the fire wall or the inner fenders. Good luck. If you don't have a better answer by noon tomorrow, I will try to send a picture from a manual I have at work.

ALT14 = ♫

http://www.tedmontgomery.com/tutorial/altchrc.html

Thank you.

A '91 Tempo is a Ford EEC-IV vehicle, so there will be an OBD-1 connector in there somewhere. Most Fords that I've played with had the connector near the passenger side of the firewall, but they can be tucked in the fenderwells or up around the radiator supports. Hunt around, maybe it was stuffed up underneath or behind something. Once you do find it, this site might help you: http://www.thorssell.net/hbook/eectest.html.

Update: A friend of mine who has a '91 says his OBD-1 connector was on the front of the passenger side shock tower. I hope this helps.

Instructions, pictures and codes...

http://freeautomechanic.com/diagnostictroblecodes7.html

Thanks, Looks like good info. Do you happen to know what the O, R, and M letters mean on the 3 digit code table?

No problem, I found the meanings. Thanks.

You will find this very interesting

The connector is in the right rear of the engine compartment near the cowl. The connector has 6 wires. If you hold the connector with the female terminals looking at you it will have 2 holes on the top and 4 on the bottom. The 2nd hole from the left is the Self Test Output Terminal. Next to this 6 wire connector is a single wire pigtail. It is the Self Test Input Pigtail. Set your voltmeter to read 12V scale and hook the positive lead to the positive battery terminal. Hook the negative lead of the voltmeter to the Self Test Output Terminal (2nd hole from the left), then jumper the Self Test Input Pigtail to the top right terminal of the 6 wire connector. Turn the key to the on position and the codes will flash the check engine light.

There is a OBD connector on this vehicle. It should be under the hood. You can use a code reader to read the codes, or a scan tool to both read codes and check the data stream, if it has a readable data stream. Some Fords of this earlier vintage do not have a readable data stream.

What exactly is going on? More information on your performance issues would be helpful.

No performance problems to report. The light just comes on after a few minutes of driving. Nothing else seems to be affected. When we turn off the ignition and then restart the car, the light stays off until it has been running a few minutes: sometimes this takes 15-20 minutes; sometimes 2 or 3 minutes.

The EGR system, and the O2, sensors have some tests that do not run until after complete warm up, and some steady state driving. These two systems would be a good place to start testing. Put the right thing to do is get some readings from your on board computer. Good luck.