Oddball electrical issue

[krman68]

I just experienced an odd electrical issue with my 13 GT 500.

I drove the car home from work ( about 35 miles). Hit the gym and go to head home. I get in and insert the ignition key, turn it as I am pressing the clutch in. The engine doesn't turn ( similar to turning the key without the clutch in) With the key on on, The tach starts flipping back from 8k to 0 and back as well as a few other gauges.... Seemed possessed.

I pulled the key and tried again...as I turned the key before it turned over, the gauges again go haywire again. The engine starts and I thought all was well. I start driving home and notice my check engine light is on. I keep checking my gauges and readings. Temp, Oil pressure and temp normal, charging normal, air / fuel keeps fluctuating between 14-20 and i noticed the computer shut off my S/C. No boost. Couldn't get it to kick in on hard acceleration. I figured the computer put the car in limp mode. It drove normal just no boost. My 03 cobra did this on occasion when it got too hot.

Get home, shut it off 2x , start it back up. Same symptoms. So I disconnected the battery to reset the computer. Once hooked back up, everything was fine...no check engine light and took it out andS/C worked fine

Anyone have any similar issue? Any idea what it could be

Thanks
Jack

 

[carguy19]

i noticed the computer shut off my S/C.

I hate when this happens. How did you turn it back on?
Maybe you can wire in your own switch so if it shuts off again you can override it and turn it back on. :-D


In all seriousness now, I would go to the dealer just to be safe. Check your intercooler pump. Sounds like IATs are high and the car is pulling timing to protect the motor.

Sorry to hear that happened to you.

 

[1TUF14SHELBY]

I'm no mechanic but stuff like this that's happened to me in other cars always seems to come back to a bad battery.

 

[Snoopy49]

I wonder if the OK button on your steering wheel is sticking. It sounds like the you were in the Engineering Test Mode. Our car have an "OK" rather than the "Reset" button.

To enter the IPC self-diagnostic mode, begin with the ignition key in the OFF position. Press and hold the message center RESET button. Turn the key to the RUN position and hold the RESET button until the display indicates ENGINEERING TEST MODE, usually within 3 to 5 seconds. Press the RESET button once to advance through each stage of the self-test.
To exit the IPC dealer test mode, turn the ignition to the OFF position.

Check and see if the center cluster says "Gauge Test".
Here is what happens when you use the Engineering Test Mode to check the gauges.
Carries out the gauge sweep of all gauges, then displays the present gauge values. Also carries out the checksum test on Read-Only Memory (ROM).

 

[krman68]

Snoop, now that you mention it and rethinking my steps when I got in the car, I may have inadvertently hit the OK button when I turned the key. I was rushing to get in the car, start it and get moving.

I drove it again this morning without issue. I don't believe it is the battery but I will keep it in mind if this continues.

Thanks for the suggestions and info

 

[carguy19]

Snoop, now that you mention it and rethinking my steps when I got in the car, I may have inadvertently hit the OK button when I turned the key. I was rushing to get in the car, start it and get moving.

I drove it again this morning without issue. I don't believe it is the battery but I will keep it in mind if this continues.

Thanks for the suggestions and info

Definitely check the intercooler pump.

From having an 04 cobra and another GT500, Ive learned quickly that is usually the culprit when the IAT's are high and the car pulls timing. They have a history of failing and the connections loosening up from vibration etc.

You can start the car and open the intercooler reservoir and see the coolant circulating to confirm that the pump is working. It will take you 30 seconds to check. I would make this a habit once a month or so to make part of your maintenance routine when you check your oil, check your tires, wash your car and do your underhood inspection.

Just an added layer of protection.

 

[krman68]

An update...the car was starting fine but when I turned the key the tach would sweep back and forth and the battery light would flash....thought it was the battery so off to the dealer. Turns out they are replacing the Powertrain Program Module....

I am not sure what this does but it sounds like the engine management system - anybody know what function this module controls/does?

 

[BOSSPOWER]

I'm no mechanic but stuff like this that's happened to me in other cars always seems to come back to a bad battery.

Happened to me in 2012 Boss 302, and it ended up being the battery. The voltage in our cars has to be perfect for it to work properly.

Regards,

Manuel

 

[Snoopy49]

From the 2014 Mustang Service Manual

Powertrain Control Module (PCM)
The center of the engine control (EC) system is a microprocessor called the PCM. The PCM receives input from sensors and other electronic components (switches, relays). Based on the information received and programmed into its memory, the PCM generates output signals to control various relays, solenoids and actuators.

 

[FordService]

I just experienced an odd electrical issue with my 13 GT 500.

I drove the car home from work ( about 35 miles). Hit the gym and go to head home. I get in and insert the ignition key, turn it as I am pressing the clutch in. The engine doesn't turn ( similar to turning the key without the clutch in) With the key on on, The tach starts flipping back from 8k to 0 and back as well as a few other gauges.... Seemed possessed.

I pulled the key and tried again...as I turned the key before it turned over, the gauges again go haywire again. The engine starts and I thought all was well. I start driving home and notice my check engine light is on. I keep checking my gauges and readings. Temp, Oil pressure and temp normal, charging normal, air / fuel keeps fluctuating between 14-20 and i noticed the computer shut off my S/C. No boost. Couldn't get it to kick in on hard acceleration. I figured the computer put the car in limp mode. It drove normal just no boost. My 03 cobra did this on occasion when it got too hot.

Get home, shut it off 2x , start it back up. Same symptoms. So I disconnected the battery to reset the computer. Once hooked back up, everything was fine...no check engine light and took it out andS/C worked fine

Anyone have any similar issue? Any idea what it could be

Thanks

Hello krman68,

I recommend you have your Ford Dealer check it out and make sure there’s nothing else going on. Also, let me get this escalated to the customer service manager for your area. Please, PM me with your VIN, dealer, mileage, full name, and best daytime number.

Deysha

 

[krman68]

Hi Deysha

Sorry for the delay responding. Was busy with things. I took it to John Kennedy Ford in Conshohocken Pa. They took good care of me. Apparently they diagnosed it and replaced the Powertrain Control Module. I picked it up yesterday and it runs fine now.


Thanks much for reaching out. Much appreciated. The dealer took good care of me. Hopefully this is an isolated incident.

 

[FordService]

Hi Deysha

Sorry for the delay responding. Was busy with things. I took it to John Kennedy Ford in Conshohocken Pa. They took good care of me. Apparently they diagnosed it and replaced the Powertrain Control Module. I picked it up yesterday and it runs fine now.

Thanks much for reaching out. Much appreciated. The dealer took good care of me. Hopefully this is an isolated incident.

That’s great, krman68! Thank you for the update and the kind words. I’m here if you need me.

Deysha

 

[93 347 Cobra]

Interesting. I've never had those issues but I started my car once and all the displays when into some kind of diagnostic mode. I have a non-Nav car and a whole bunch of items showed up in the radio display like A/C fan levels and the fans started ramping up in speed. I thought it was odd but I quickly turned the car off and restarted it, hasn't happened since a few months ago. I'd love to figure out how to get the a/c fan levels to display all the time.