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Car died and wouldn’t go over 1000Rpm or 5mph

zanethan

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#1
Of course this happened in the middle of rush hour.

Car is a 2015 ST with 19,000 miles on it. Dizzy stage 2 tuned.

I’m driving, come up to a stop light and start lightly braking. Come to a full stop and then the ST just shuts off. All gauges reading normal. Dashboard lights up like a Christmas tree (check engine, wrench, battery, abs, traction control) all go off. Start button becomes unresponsive. Finally I get it to respond and the car starts but won’t go above 1000 rpm or 5 mph. I manage to get out of the way of traffic. Turn it off and then turn it on. Acts like nothings wrong. I chalk it up to a weird glitch. Set off again and everything g is normal for 200 yards. Car doesn’t stall this time but dashboard lights up and won’t go over 5. Immobilizer malfunction warning begins to come and go. Stays running long enough for me to make it to a parking lot. Turn it off again. Give it a few seconds and place the key in the cup holders. It starts back up normally. Start driving home at this point and everything stays normal for the next 15 minutes or so. Get home turn it off and back on, normal. Use my AP to check for stores codes and I get the following. P0504, P060D, P193E, P2127, P2610, U0155, U0167, and finally U0422. I uninstalled the AP in case it happens again. After going back to stock again everything is normal. Drove around for 10 minutes without incident. Anyone have any thoughts?

Worth noting radio acted normal through this entire fiasco.



 


TyphoonFiST

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#3
Of course this happened in the middle of rush hour.

Car is a 2015 ST with 19,000 miles on it. Dizzy stage 2 tuned.

I’m driving, come up to a stop light and start lightly braking. Come to a full stop and then the ST just shuts off. All gauges reading normal. Dashboard lights up like a Christmas tree (check engine, wrench, battery, abs, traction control) all go off. Start button becomes unresponsive. Finally I get it to respond and the car starts but won’t go above 1000 rpm or 5 mph. I manage to get out of the way of traffic. Turn it off and then turn it on. Acts like nothings wrong. I chalk it up to a weird glitch. Set off again and everything g is normal for 200 yards. Car doesn’t stall this time but dashboard lights up and won’t go over 5. Immobilizer malfunction warning begins to come and go. Stays running long enough for me to make it to a parking lot. Turn it off again. Give it a few seconds and place the key in the cup holders. It starts back up normally. Start driving home at this point and everything stays normal for the next 15 minutes or so. Get home turn it off and back on, normal. Use my AP to check for stores codes and I get the following. P0504, P060D, P193E, P2127, P2610, U0155, U0167, and finally U0422. I uninstalled the AP in case it happens again. After going back to stock again everything is normal. Drove around for 10 minutes without incident. Anyone have any thoughts?

Worth noting radio acted normal through this entire fiasco.



Replace your Keyfob batteries see if that helps


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maestromaestro

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#4
Replace your Keyfob batteries see if that helps


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I doubt that it has any impact. Once the car started, it's no longer looking for the fob until the next start.

If the main battery IS a culprit, I am curious why it would go into the complete limp mode. When mine overheats, it allows me to drive at a decent pace - 5 mph is rather odd (unless Ford has a "Level 2" limp if it detects a major system failure).
 


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zanethan

zanethan

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Thread Starter #5
Replace your Keyfob batteries see if that helps


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I had that thought too but I forgot to mention that after getting it home I kept the key in my pocket and no issue. Plus a dead key fob battery wouldn’t throw codes would it?
 


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zanethan

zanethan

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Thread Starter #6
Battery issue is my bet. Check cables for corrosion. Have the battery tested.


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Battery terminals are clean and tightened. I’ll get the battery tested though. No other symptoms of a failing battery though.
 


TyphoonFiST

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#8
The Hot heat takes a toll on the battery.




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zanethan

zanethan

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Thread Starter #9
Well it’s not the battery. On the way to AutoZone the stability control light did come on. Upon restarting that’s gone. So what’s everyone’s next guess??
 


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zanethan

zanethan

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Thread Starter #11
did you check the fuse on the positive cable?
No I wasn’t aware there was a fuse there. It’s worth noting the battery had a 100% charge on it so I do t think it’s battery related. But I’ll check the fuse just to make sure
 


koozy

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#12
No I wasn’t aware there was a fuse there. It’s worth noting the battery had a 100% charge on it so I do t think it’s battery related. But I’ll check the fuse just to make sure
Did they load test it. 100% charge, but could still fail load and emit weird issues that is being described.

Here's a sample load test. https://www.fiestastforum.com/threads/17078-Battery-Maintenance?p=334731&viewfull=1#post334731
 


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zanethan

zanethan

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Thread Starter #13
Did they load test it. 100% charge, but could still fail load and emit weird issues that is being described.

Here's a sample load test. https://www.fiestastforum.com/threads/17078-Battery-Maintenance?p=334731&viewfull=1#post334731
I believe they did. I would have asked but 90% of the employees at AutoZone have no idea what you’re saying. My sight glass is also as green as an Irish pasture.

Edit-checked the acid levels which were good and the voltage never dropped below 10 while cranking. I think it’s safe to say the battery is good here.
 


koozy

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#14
Next thing I would go over are body/chassis grounds. There’s a couple main ones in the engine compartment. Also check the ecu harnesses next to the battery, someone else actually had a loose connection that was causing issues.


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maestromaestro

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#15
It doesn't sound like a battery. Perhaps there's a loose contact - to the left of the battery tray, there are two large multi-prong clamped harness connectors. I'd check those to make sure, dirt and grime may get in.

Your symptoms indicate some major system issue. I wonder if this has anything to do with ECU or canbus.
 


Clint Beastwood

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#16
i had something similar happen, after switching tunes when the car said "wait xx seconds before starting" i brain farted and just started the car - felt horrible, no power steering, car felt grumpy then died and dash lit like an xmas tree.

shut off for 30 seconds, started, then fine.
 


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zanethan

zanethan

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Thread Starter #17
But mine happened after being tuned for months. I have since switched back to the stock tune in case it has to be towed to a dealer.

The more I look into those codes the more it looks like a loose connection or short. It’s just almost impossible to trace cause there are no codes to point me in any direction.
 


TyphoonFiST

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#18
I think you should check the connector at the PCM as I also remember correctly there was another member who had a corrosion issue and water had gotten into the "weatherproof" connector and it needed to be repined and sealed.....[popcorn]
 


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zanethan

zanethan

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Thread Starter #20
I think you should check the connector at the PCM as I also remember correctly there was another member who had a corrosion issue and water had gotten into the "weatherproof" connector and it needed to be repined and sealed.....[popcorn]
Where is the PCM located?

Also does anyone have a wiring diagram of chassis grounding locations. I’m curious if the PCM and stability control module share a common ground.
 


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