Code 542 No Start - 1994 GT

[five0xpres]

I recently had my neighbor do some work on my car to get it ready for the annual safety inspection. Namely replacing the front brake pads and turning both rotors to solve a vibration under braking issue I had and replacing the driver side parking/turn signal assembly . that was broken in an fender bender sometime ago.

He is a auto detailer by trade, but is also handy in turning a wrench...having also replaced the front wheel bearings and the driveshaft u-joints a few months ago for me. So I trust in his ability and general mechanical knowledge. The brake job went off smoothly, but he discovered that the mounting points for the parking/turn signal piece had been broken in the accident as well and needed to be replaced before he could finish the other repair. This required removing the headlights and the grille to get to the mounting bracket, which runs the whole width of the front end behind the headlights, etc. He also had to remove the driver's side fender to bend it back to closer to factory spec after said accident to make sure the opening lined up when he put the lens back into place.

He completed the work and got the car back to me in a couple of days, the mounting piece took 2 days to be shipped, and it looked great, considering how it had looked since the day I spun out on an icy overpass and brushed the concrete bridge wall. The braking under vibration was also gone, after already having the tires balanced and the front end aligned in an attempt to track down the cause in the previous months.

I took the car for inspection earlier this week and it passed with no problems. Drove it back and forth to work without drama. Went to start it to go to work yesterday and nothing. It turns over, but won't fire. I had to get to work so I had to leave it sitting in the garage while I took a friend's Jeep to work. Got home and hooked up the trusty Actron code scanner and got the aforementioned code 542 - Fuel Pump (FP) circuit open connection - Eletronic Control Assembly (ECA) to motor ground. I also noticed that the fuel pump does NOT prime when the key is turned to ON. I searched the forums and found an article that mentions being able to ground the fuel pump at the self-test connector in the engine compartment, which I did. I can hear a click near the radiator, which I'm guessing is the computer signalling the fuel pump relay to engage, but still no sound from the fuel pump out back.

It is possible that the fuel pump has really bitten the dust, the car does have close to 270,000 miles on the original (as far as I know) pump. If it is, then it defies all automotive break down odds....the car is in it's home garage and there is about 1/4 tank of gas in it at the moment, which is unheard of in this type of failure. I'm also thinking that a possiblity might be that I might have a loose ground to the fuel pump, if there happens to be one near the front clip...considering that my neighbor just did work in that area within the past week.

Does anyone happen to know where the ground(s) are in the front end of the 1994 Mustang GT that might be a possible cause to this problem? Like I said, it might be the actual fuel pump, but I'd like to rule out a possible quick fix instead of investing that much time into a fuel pump swap and have it not fix the problem anyway. Thanks for any help provided!

 

[five0xpres]

Well since I didn't get any answers, I guess we'll have to tackle it in stages. My neighbor is planning to come by tomorrow and drop the gas tank down and test if there is power going into the pump at the connection on top of the tank. If there's no power there, I guess we'll just backtrack the lines and try to find where the break in the connection is. And if there is power to the pump, I guess then the pump is probably in need of replacement.

 

[toyman]

There should be a battery to chassis ground just above the driver's side headlight assembly. The other important ground is the battery to engine. For the fuel pump make sure the inertia switch wasn't tripped. It's located in the trunk on the driver's side. Should be marked.

 

[99FiveOh]

Also, there are wires running directly into the fuel tank, you can access the connector under the rear bumper. You can simply run a ground and 12 volts to that connector and see if the pump comes on at that point. This will eliminate all the wiring and circuits/switches up to that point.

If you power the fuel pump at this point and it does not come on, it's safe to say you need to replace it. And a fuel pump swap isn't that bad of a job anyway. It'll take the better part of an afternoon to pull it down and replace the pump, just make sure you have the quick disconnect tools prior to starting work.

And with the miles that are on your car now, a new fuel pump can't hurt regardless if it's the problem or not!

Oh btw, you can remove the front bumper and driver side fender without interfering with any grounds or wiring, so I doubt this was caused by your friend working on the car. It is possible that he could have taken some grounding straps off by mistake thinking they needed to be removed, but you can verify this by looking by the battery and you'll see 2 wire terminals bolted down, usually with green 8mm head bolts.

 

[toyman]

You can also test the fuel pump by grounding the FP lead at the DLC (data link connector) short side with the ignition switch in the on position. If it doesn't turn on and the inertia switch isn't tripped there is either a problem with the pump or the power lead to the pump.

 

[five0xpres]

Thanks toyman and Nota4.6 for the suggestions/ideas. When I got home this morning from work and read your replies, I was going to pass that info onto my neighbor....unfornately, he came and towed the car over to his place to work on it while I was catching a nap from a rough night at work.

I haven't heard from him, probably because he still thinks I'm asleep, but I'm going to get in touch with him shortly to see how goes the progress. I'll post an update when I find out more of what's going on.

 

[five0xpres]

Just an update on my Code 542 - No Start issue:

After talking to my neighbor yesterday and today, he dropped the tank and discovered that there was indeed power to the fuel pump at the tank, but he still couldn't get it to prime. Ordered a new one yesterday and it came in today. He's wrapping up the install as I type this and he told me that they energized it for just a second to see if it was ok and he said the pump turned on when they hooked it up.

I can't type how much stress and worry is now off my shoulders. I was hoping it was just the fuel pump and not something more serious and expensive. But I must say that after 17 years and almost 260,000 miles, whoever built that pump must have been having a good day that day.

 

[five0xpres]

Got the car back and drove it to work this morning and it's running just a good or better than before. Not sure what brand of pump, cost is more a consideration that max performance, but it's much quieter than any other Mustang fuel pump I've ever heard/owned.

I checked for codes, to make sure I had corrected them all, and got 1-1-1, System Pass. That made me happy...but I did have the Air Bag Indicator light flash a code 52 on my way to work. I checked around and found out it's a power interruption to the Air Bag module, which is understandable since the battery had been disconnected for 2 days.

To reset it, I had to access the Air Bag Diagnostic connector under the glove box. After starting the car, I had to wait until the Air Bag Indicator light had flashed the code 52 the first time. Then I used a jumper wire to connect the outer pins in it until there is a tone from the Air Bag Diagnostic Module (approx 5 seconds). Then I removed the jumper wire and shut the car off. To verify it was cleared, I restarted the car and waited to see if the light on the dash came back on, which I can report it didn't. So I think I'm good to go again for the foreseeable future.

Except I need to track down a new pair of gas tank straps, mine are showing a fair amount of rust. My neighbor is sure that they'll last until atleast next year, since our winters here in North Carolina aren't usually that bad. But he told me I should keep an eye on them and if I notice the start of any breaks in them, to get them replaced pronto. It's always something.

Oh, I also passed 270,000 miles on the way to work this morning. This Hoofbeat of America still runs strong.

 

[99FiveOh]

I have a good set of the straps on my parts car, I'm not really sure what they are worth.

Glad to see you got the problem fixed, it's always nice to have our cars back to normal after BS starts happening!

 

[five0xpres]

Thanks for the offer, Nota4.6, but they aren't that expensive at Advance Auto for a set; about $30 so I ordered them today. Should be in tomorrow after 7:30am and then I'm onto the next project...time to replace the plugs and do an oil change. LOL