Car turning off randomly

[FrankM5]

Hey guys,

Yesterday on my way home, my car turned off on me while coasting/breaking at a red light. Did it to me about 3 times, the first 2 back to back. I have 46k miles on the car right now. Im lost for words on what this issue can be. The car will be coasting/ breaking then it shows up on the dash, "Shift to Park to Start Vehicle". The only "light" that shows up is a battery one.

After that happened i really started to look for possible issues or something the car might be doing weird. I did notice the throttle response on the car was not where it needs to be, when im on the highway going 60 the car hangs on 8th gear for some reason in the same rpm. It kinda feels odd when you let go of the gas too, but also when you coast going 60+ then you kinda tap/push lightly on the gas pedal to keep the car at the same speed it seems like it either lags or requires a bigger push, but a bigger push would cause the car to downshift.

I also have that issue where the car shakes on idle sometimes, the Air/Fuel ratio goes low than high. SO im not sure if this is all tied in with each other. In terms with the MAF sensor/ Throttle body / fuel system. No codes on the car btw.

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[KingKona]

I'll guess it's your battery.

 

[Mspider]

mods?

 

[FrankM5]

I'll guess it's your battery.

battery was replaced a year ago. Nothing else shows indication of the battery going bad. I could be wrong.

 

[FrankM5]

mods?

Just a catback, although it does have an exhaust leak.

 

[KingKona]

battery was replaced a year ago. Nothing else shows indication of the battery going bad. I could be wrong.

You might have gotten a bad battery.
Or some bad gas.

 

[tom_sprecher]

As far as your first issue, my engine has stalled maybe twice in the past 6 years. Same situation when coasting to a stop. I chalked it up to an ECU glitch or stack overflow, and figured I can not troubleshoot an issue that happens very rarely.

I got nothing regarding your throttle response. Mine has been great after installing the FP PP2.

 

[Toretto]

I had a similar issue when I picked up my '21 GT back in July.....2 trips to the dealership resolved nothing, so I took it upon myself to do more research and ended up doing a KAM reset beginning of August and so far so good. This is what I did:

- Disconnect battery cables
- Connect Positive and Negative cables together (you can use Y clips or in my case, jumper cables) and let that sit for 15 mins to fully discharge the module capacitor (make sure you keep this away from any metal, etc.)
- Reconnect cables to battery, lock the car and walk away with your keys for 15 mins so the car can go into full sleep cycle
- After that, start the car and idle for 5 mins, revving it every 30 seconds
- Drive the car for 15 mins slow at first and then faster (basically, drive it at different intervals)

The idea behind a KAM reset is that, from what I was told, is that sometimes cars learn poor idling strategy while the car is in transit from the plant to various stops before finally arriving at your dealership.

Hope this helps.

Eric

 

[Toretto]

You'll definitely notice throttle response improving (at least initially) after the KAM reset; I definitely did.

 

[joe603]

When you say coasting...do you put it in neutral or keep it in gear?

 

[2022 Mach 1]

You'd be amazed at what a bad alternator can do as well. Check your voltage at idle. Anything lower than 13.7v could indicate a poor charging alternator and may need to be replaced.

 

[mkcotton]

I'll guess it's your battery.

I agree, but check your alternator output. Should be 14 v min. If it is test your battery.

 

[FrankM5]

When you say coasting...do you put it in neutral or keep it in gear?

I mean keep it in gear sorry, its a 10 speed lol

 

[FrankM5]

You'd be amazed at what a bad alternator can do as well. Check your voltage at idle. Anything lower than 13.7v could indicate a poor charging alternator and may need to be replaced.

Hmm interesting.. i will look into it.

 

[FrankM5]

I had a similar issue when I picked up my '21 GT back in July.....2 trips to the dealership resolved nothing, so I took it upon myself to do more research and ended up doing a KAM reset beginning of August and so far so good. This is what I did:

- Disconnect battery cables
- Connect Positive and Negative cables together (you can use Y clips or in my case, jumper cables) and let that sit for 15 mins to fully discharge the module capacitor (make sure you keep this away from any metal, etc.)
- Reconnect cables to battery, lock the car and walk away with your keys for 15 mins so the car can go into full sleep cycle
- After that, start the car and idle for 5 mins, revving it every 30 seconds
- Drive the car for 15 mins slow at first and then faster (basically, drive it at different intervals)

The idea behind a KAM reset is that, from what I was told, is that sometimes cars learn poor idling strategy while the car is in transit from the plant to various stops before finally arriving at your dealership.

Hope this helps.

Eric

Although i agree with the KAM reset i have done it a handful of times in the past, but my car is turning off so i dont think its related. Personally i feel like the throttle body might be going bad or something.

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