A couple of weeks ago, my car wouldn't start after sitting in a parking lot in cold weather for a couple of hours. (I park it in an unheated garage at home). I had it towed to a garage and after sitting in their garage overnight, it started for them. They checked it over and found that it needs a tuneup (plugs, air filter & fuel filter). They also said it may have had a little gasline freeze. I put heet in it and filled the tank. It ran fine for the next several days. Then my husband was on vacation for over a week and the sable sat in the unheated garage for over a week without being ran while we used our SUV. The wind chill temps got down to about -20 to -30 during this time. I went to use the car today and it would not start. Ironically, the temp got to about 20 above zero today. I hooked up portable heaters in the garage to warm the car, but it didn't help. My husband came home from work and replaced the fuel filter. The car started right up and then started running very rough (idling up and down) and then died. Now it won't start again and the check engine light is on. My brother suggested it might be a weak fuel pump or an oxygen sensor. Are these possibilities? How would I go about determining this without having it towed in and pay for a diagnostic again? Could the plugs being bad cause the car to react this way? (Husband is going to replace the plugs tomorrow night). Any info or advice would be greatly appreciated.

Did your husband reconnect the Inertia Switch in the trunk, after depressurizing the fuel system?


Turn the ignition switch to ON and listen to the fuel pump in the gas tank run for several seconds. After the fuel pump stops, turn the ignition switch OFF. Repeat this procedure several more times. Then, turn the ignition switch to START and it should fire right up. What this does is fully pressurize the fuel rail. If it is not fully pressurized, the car won't start. The fuel pressure in the rail may have been lost, when your husband changed the fuel filter. This likely caused the Check Engine Light to come on. Just use a code reader to clear the code.

If you can hear the fuel pump run, it is likely fine. Fuel pumps are very reliable these days. I doubt that the oxygen sensor is preventing the engine from starting.


Here's one of many links that may be of interest to you in the Sticky on how to maintain your Mercury Sable. This one should help your husband change the rear spark plugs, without totally getting frustrated:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1375876

Here's how I change the fuel filter on my 2000 Taurus, which is the same as on your Sable:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1389619

Did your husband reconnect the Inertia Switch in the trunk, after depressurizing the fuel system?


Turn the ignition switch to ON and listen to the fuel pump in the gas tank run for several seconds. After the fuel pump stops, turn the ignition switch OFF. Repeat this procedure several more times. Then, turn the ignition switch to START and it should fire right up. What this does is fully pressurize the fuel rail. If it is not fully pressurized, the car won't start. The fuel pressure in the rail may have been lost, when your husband changed the fuel filter. This likely caused the Check Engine Light to come on. Just use a code reader to clear the code.

If you can hear the fuel pump run, it is likely fine. Fuel pumps are very reliable these days. I doubt that the oxygen sensor is preventing the engine from starting.


Here's one of many links that may be of interest to you in the Sticky on how to maintain your Mercury Sable. This one should help your husband change the rear spark plugs, without totally getting frustrated:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1375876

Here's how I change the fuel filter on my 2000 Taurus, which is the same as on your Sable:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1389619

Not sure if I am posting this correctly, because it shows "answer this question" but I am attempting to respond and get additional information from TxGreaseMonkey who answered my original questions.

Thanks so much for the information. My husband was in bed when I received your reply last night, so we will not be able to try this until he comes home. If we can't hear the fuel pump running when we try this, does this mean it is bad? Should be we go ahead with replacing it or are there other things to check (ie: fuses, relays) before we go to the expense, time and trouble of replacing the pump? Also, do you have any links of step by step instructions of how to replace the fuel pump? My husband was very impressed with the instructions you gave for doing the plugs. Thanks again.

Just because you can't hear the fuel pump run does not mean it needs to be replaced. I can't really believe the fuel pump is bad. Try everything else first, especially checking the fuses and the fuel pump relay in the under hood fuse/relay box.

I don't have a link on replacing the fuel pump, but I don't think it will come to that. How many miles are on the car and do you have the Duratec 24 valve DOHC engine or the Vulcan DOHV engine?

Just because you can't hear the fuel pump run does not mean it needs to be replaced. I can't really believe the fuel pump is bad. Try everything else first, especially checking the fuses and the fuel pump relay in the under hood fuse/relay box.

I don't have a link on replacing the fuel pump, but I don't think it will come to that. How many miles are on the car and do you have the 24 valve DOHC engine or the Vulcan DOHV engine?

I did try to listen for it by myself, but it is a little difficult to turn on the key run to the back of the car and listen especially since the beeping sound that the car makes when the key is first turned to on position. In light of that, I decided I had better wait until husband comes home. We are also going to just replace those fuses when he comes home as well since we don't have a tester to check them. There are about 95,000 miles on the are. It is a 24V DOHC.

No need to start replacing fuses, yet. Have your husband just follow my procedure below and test them with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post252145

A test light only costs several dollars and is available everywhere:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=30779

He can test all of them in just several minutes. You have the same engine as in my Taurus.

Have your husband pick up a test light on the way home from work. Every auto parts store carries them.

Back to to hearing the fuel pump run. Get in the car, fasten your seat belt, lower the driver's window, and turn the ignition switch to ON. You should hear the fuel pump run (humm) for two seconds.

Will do. I sure appreciate all your time and effort on this. Will let you know what comes of it. Thanks again.

Back to hearing the fuel pump run. Get in the car, fasten your seat belt, lower the driver's window, and turn the ignition switch to ON. You should hear the fuel pump run (humm) for two seconds. Let me know if you hear it run.

We tried turning on the key to listen for the pump. We could hear something come on, but determined that the sound was more than likely coming from under the hood instead of the back of the car. We got a tester and the #16 fuse tested as good. There are no areas on the #30 fuse/relay to test it (one of those black enclosed box type things, sorry about the terminology), so we just bought a new one and put it in there and tried listening for the fuel pump again. Since we weren't sure where the sound that we were hearing was coming from, we even removed both relay fuses and turned the ignition on and still heard it, so I think that rules it out as the sound of the fuel pump. My husband then removed the cap on the Schrader valve and pressed on the needle with the key in the on position and nothing came out of it, no air or gas or anything. He put that all back together and he tried banging on the tank with a rubber mallet and that didn't do anything either. So, any other ideas or should we just resign ourselves to the fact that the fuel pump is gone?

. Test all under hood and under dash fuses with the test light. It's important to test all fuses.

. Did your husband disconnect the electrical connector from the Inertia Switch in the trunk? If he did, he needs to reconnect it and even press the reset button. It controls power to the fuel pump. It's located on the right side of the trunk, behind the liner. Inertia switches can be triggered when the car is bumped. They turn off the fuel pump if you're in a crash, so you don't fireball.

. Test for codes, by attaching a code reader to the Data Link Connector under the dash.

. Remove and fully charge the battery, if there's any doubt that there could be a problem with it.

Always begin by fully charging the battery and testing all under hood and under dash fuses with a test light or multimeter. It's important to establish a "known good baseline."

Remember, a fuse is good only if the test light comes on when each test terminal on the fuse is tested. If only one test terminal lights up, the fuse is bad or the contacts are corroded and need to be cleaned.

Do you have plenty of fuel in the gas tank?

We tested all the fuses like you suggested and they all tested okay. Of course, we can't check the larger ones that don't have the test terminals, but we did replace the #30 relay. We did check the inertia switch again and my husband also tried banging on the tank with a rubber mallet again. This time he heard something trying to start running, and assumed that it was the fuel pump trying to kick on. Also, there is a little over half a tank of gas in the car.

. Try removing and cleaning the contacts to the fuel pump fuse.

. Try turning the ignition switch in various ways to see if the problem may reside with it. Listen for the fuel pump while doing this.

. Remove Relay No. 29, clean the contacts, and reinstall.

. Test the Constant Control Relay Module, which is located just to the right of the battery. This may have to be done at the dealership.

. Check the fuel pump circuit from the relay to the fuel pump. Examine the connector.

. Check/replace the fuel pump. Replacing the fuel pump is best left to Ford.

Fuel pumps can burn out, if the fuel filter is not replaced every 30,000 miles or the fuel strainer on the pump clogs. Fuel pumps also need gas in the tank to properly cool.

Did you end up replacing the fuel pump?

Well, a friend of my husbands has more equipment in his garage (he is kind of a part-time mechanic) and he new a guy with a tow truck, so we had it towed to his garage. He had offered to do the fuel pump (if that was the problem) for $50 labor, which we just couldn't pass up. However, after sitting at his garage for a couple of days, he couldn't get it to turn over. That guy called the ford dealership and explained what it was doing and they said that the "car thinks it is being stolen" and the anti-theft component needs to be reset. The guy at ford of course refused to give any additional information, just said that we would have to have it towed in. Do you know anything about this? My husband's friend said he thinks he can "get around it" but that sounds a little onimous to me.

What Ford says could very likely be true. As many on this site have heard me say many times, I have never seen a bad fuel pump on a modern-day car. And I knew your husband checked everything out, short of replacing the pump. I'm particularly interested in your situation, since I own a 2000 Taurus. I've helped several other people where the anti-theft system was the whole problem right along. I would tow it to Ford and let them fix it, particularly since this is a stubborn electrical problem that may involve the PCM.

Please keep us posted with the solution.

Once your solve this problem, my advice is to make sure your change the transmission fluid and filter every 30,000 miles, like Ford recommends. Transmissions are the weak link on front wheel drive cars. I recommend that you use Mobil 1 Synthetic Multi-Vehicle ATF.

What was the solution to the car's problem?

Well, once we got it to the dealership, they determined that the PCM module was bad. They ordered it and put that in and reset the codes (cost of $909). The car still would not start and they determined that the fuel pump was, indeed, bad as well. They wanted to charge us $650 to fix the fuel pump, so we had it towed over to a friend's garage and he replaced the fuel pump for us and with tow and everything it was $250, so that was good. It is now running fine. I thank you for all your help throughout this situation.

Do you believe the PCM and fuel pump were both bad?

Your situation was one of the most involved I've seen in a long time. I so glad you have it behind you.

Yes, I actually believe it because of the involvement of my husband's coworker before going to the dealership and the afterward when he got the car back and confirmed the fuel pump problem. I am glad it is behind us at this point as well. Thanks again for you help throughout the process.

Almost the same problem as you have that the Engine Check light is lit up the day before yesterday 6/25/10 Friday, and within 2 days till today 6/27/10 I fixed it.
I am a school bus driver. 6/25/10 I was back home late because my summer campus route practice from midtown to downtown Manhattan. My car 2003 mercury sable premium LS parked in the sun from 12:00pm to 6:30pm. I drove home by 6:55pm and got my car fueled at a gas station near by my home. I tightened the gas cap. However, when I drove back into my gauge, I backed too much almost hit the back wall, so I immediately shifted to forward. I never did this before that shifted the back and forward too fast and too hard, then gave me a shock, the ENGINE CHECK light lit up and won't go away. But my car mileage is only 39,119! How could it be? I came to this website and read some info as "Get in the car, fasten your seat belt, lower the driver's window, and turn the ignition switch to ON. You should hear the fuel pump run (humm) for two seconds."

My car 2003 mercury sable LS 39,119 miles, backed off too hard and then too fast shifted forward to park into my gauge, then ENGINE CHECK light lit up. I got in the car, fasten your seat belt, lower the driver's window, and turn the ignition switch to ON. I heard the fuel pump run (very light "humm") for one second, (but the sound is very very light, if my ear is not sharp I could not even hear it), and then I heard a big sound (Humm!! )under the hood which is the front fan pump. This is enough for me to know my fuel pump is good. Now I came to figure it out why the Engine Check is lit up. I went to Radioshak and got a multimeter with two testing pens, one red, one black which is 26 dollars plus tax total 29 dollars. Why? Because the lighting tester won't work in the right way! I took off all the fuses from the black colored Fuses Compartment box under the hood close to the battery by opening the cover of the box. I carefully put them down one by one and wrote down their numbers in order, I did not see #16 but only #10, #15, #20, #30, #40, #50, it's funny, when put #20 up set down, it became into #02, but I just followed the way two of the #20 had been as they were up set down as #02. I cleaned the fuses, then I used my multimeter red pen as positive touched one end of a fuse and used the black pen as negative to touch the other end of this fuse, while the multimeter control arrow pointed to" R x 1" of OHMS range, then the indicator pointed to 10 of OHMS, which meant that this fuse is in good of resistance condition and was not blown up. I tested all the fuses one by one, and then I put them back to the box one by one in order accurately. None of the fuses is in problem that is the answer from the test. When I was testing the fuses, a neighbor of mine walked by and gave me a "Humm!" meaning my car is in a problem, but I don't care what she laughed at, I just focused on my job. I covered back up the cover of the Fuses Compartment box and then close the hood. I redo again , got in the car, fasten my seat belt, lower the driver's window, and turn the ignition switch to ON. I heard in the back the fuel pump run (very light "humm") for one second, and then a very loud sound "humm!!!" from the front under the hood which is the front Fan pump. I did twice of this, I saw the ENGING CHECK light be there the same, still won't go away. Then I turn the key to start the car engine after ON. When the engine is on, I saw the ENGING CHECK light just stayed for 3 seconds, and then gone. I fixed it!

The reason of my car ENGING CHECK light lit up is because the lean level of the fuel in my car tank when I backed up very fast and then I forward up very fast which made the level of the fuel in lean which caused the oxygen senser give car computer a signal that the fuel supply system is short of fuel to support the engine , meaning misfire in the engine. Therefore, this problem is faulse problem, can be fixed by move away all the fuses from the fuse box and then put them back up as they were. In addition, today I replaced the fuel filter too. My car changed the fuel filter when it was in 15000 miles, by30,000 miles I was supposed to do it again but I didn't. Today is 39,119 miles which is 9119 miles over the schedule.

I had the same problem on my 2000 Sable. Have been able to pull the hose off the filter and move the switch to start for a few moments to clean the line and put it back. That didn't work today so I found this page and reseated the relays and it started right up. That wasn't the first of your suggestions that I tried, but that fixed it. Thanks for the list of things to check. You saved the day.

Guest42, is this the suggestion that worked, "Remove Relay No. 29, clean the contacts, and reinstall?"

I go an extra step and apply a light coat of dielectric grease to the cleaned relay and fuse contacts; i.e. military preparedness.

It was dark so I reseated all of the relays. I am going to have to clean the contacts though, or possibly replace 29, because I had the same problem twice yesterday while out of town. I learned a lot from the military too, but probably will not take the extra step unless it is necessary (I'm doing good to keep my oil changed.)