Engine shuts off while driving - SOLVED

[sasso]

Also there is spark and fuel. Pressures are good on crank and fuel is being delivered

 

[blanchard7684]

I would try to see if the issue can be whittled down to steering, brake, or if it has to be both.

 

[viven44]

If it is still under warranty, Tow it back to a different dealer and don’t leave until it’s fixed for good.

As a matter of principle, (and to not give GM an excuse that you tampered) I don’t think anyone should be bothered and take matters into their own hands with a vehicle under factory warranty. If the dealer cannot fix it then pursue remedy with GM, and so on

 

[sasso]

If it is still under warranty, Tow it back to a different dealer and don’t leave until it’s fixed for good.

As a matter of principle, (and to not give GM an excuse that you tampered) I don’t think anyone should be bothered and take matters into their own hands with a vehicle under factory warranty. If the dealer cannot fix it then pursue remedy with GM, and so on

I wish I could take it another dealer. We only have one.

 

[sasso]

The main thing on my mind is, what can cause it not to start right back up. If we figure that out then we can figure out what the problem is.

 

[sasso]

By the way, checked and cleaned all ground points

 

[jfoj]

Questions

1. How many miles on vehicle?
2. Is the battery original?
3. How do you know it has fuel pressure?

A few comments

1. Not sure you are aware but these vehicles have Adaptive Charging Systems. The ECM commands the alternator to turn off and will run the vehicle only on the battery sometimes down to 12.2 Volts before the alternator is turned back on. If the battery is bad, the Voltage could drop too low causing the engine to stall, then the starter could crank the engine, these starters typically have rare earth magnetics and do not need the current the older units needed. If the cranking Voltage is low, modules do not communicate and often you may not get strong/consistent spark and/or injector firing.

I would have the battery checked and/or replaced.

2. You will not always get codes. For example if the FCPM goes bad, the vehicle has no ability to see the output of the FCPM to fuel pump to monitor anything. You would think that maybe the common fuel rail pressure would drop and trigger some sort of low fuel pressure code, but I have never heard anyone state this occured. Maybe is has and nobody has mentioned it. I know you can monitor the high pressure side of the fuel rail, I need to check and see if the low pressure fuel can be monitored.

3. IMHO one of the best trouble shooting tools is Starting Fluid. Go spend the $4 or so to buy a can of Starting Fluid and keep it in the vehicle. Make sure you have what ever is needed to get the air filter box open so you can spray a good 5 count of starting fluid in toward the air intake and then try to start the engine. Usually if the engine starts and dies, you have a fuel problem, if the engine cranks and does not even kick or start you have an ignition problem.

4. Do you have any sort of scan tool? You do not need sometime very advanced, anything is better than nothing. What phone platform are you using? Apple or Android? You can get OBDII apps for your phone and a Bluetooth OBDII interface for typically under $40 and you will always have at least a basic scan tool with you at all times.

 

[sasso]

Questions

1. How many miles on vehicle?
2. Is the battery original?
3. How do you know it has fuel pressure?

A few comments

1. Not sure you are aware but these vehicles have Adaptive Charging Systems. The ECM commands the alternator to turn off and will run the vehicle only on the battery sometimes down to 12.2 Volts before the alternator is turned back on. If the battery is bad, the Voltage could drop too low causing the engine to stall, then the starter could crank the engine, these starters typically have rare earth magnetics and do not need the current the older units needed. If the cranking Voltage is low, modules do not communicate and often you may not get strong/consistent spark and/or injector firing.

I would have the battery checked and/or replaced.

2. You will not always get codes. For example if the FCPM goes bad, the vehicle has no ability to see the output of the FCPM to fuel pump to monitor anything. You would think that maybe the common fuel rail pressure would drop and trigger some sort of low fuel pressure code, but I have never heard anyone state this occured. Maybe is has and nobody has mentioned it. I know you can monitor the high pressure side of the fuel rail, I need to check and see if the low pressure fuel can be monitored.

3. IMHO one of the best trouble shooting tools is Starting Fluid. Go spend the $4 or so to buy a can of Starting Fluid and keep it in the vehicle. Make sure you have what ever is needed to get the air filter box open so you can spray a good 5 count of starting fluid in toward the air intake and then try to start the engine. Usually if the engine starts and dies, you have a fuel problem, if the engine cranks and does not even kick or start you have an ignition problem.

4. Do you have any sort of scan tool? You do not need sometime very advanced, anything is better than nothing. What phone platform are you using? Apple or Android? You can get OBDII apps for your phone and a Bluetooth OBDII interface for typically under $40 and you will always have at least a basic scan tool with you at all times.

1. 36k kms
2. no, second battery, about 5 months old
3. checked it using the scan tool and removed the fuel delivery pipe to see if fuel is flowing during crank.

I tried jump starting it to no success.

we tried starter fluid, did not help

yes, using an advanced scan tool, 0 codes and 0 modules offline

 

[viven44]

I wish I could take it another dealer. We only have one.

Well then, back to the same dealer.

"what can cause it not to start right back up. If we figure that out then we can figure out what the problem is."

With all due respect, the dealer still is best equipped with GM factory manuals to troubleshoot that. If they can't fix it, GM will have to.

Forums and YouTube videos in my experience are best for building up a knowledge base over the years, and the best resource on year models that have been out of warranty for years and has DIY or shop knowledge built up.

I am a Hotrodder myself, tearing apart engines, transmissions, and axles on old trucks, so deep down I love a challenge, but I really mean it here that on something under warranty they are legally obligated to fix this for you for free

 

[blanchard7684]

1. 36k kms
2. no, second battery, about 5 months old
3. checked it using the scan tool and removed the fuel delivery pipe to see if fuel is flowing during crank.

I tried jump starting it to no success.

we tried starter fluid, did not help

yes, using an advanced scan tool, 0 codes and 0 modules offline

So verified spark and fuel.

If you are positive you have fuel delivery up to the injectors then the next thing is making sure the injectors are getting a signal to pulse

Are you able to disconnect an injector to see if it is getting a pulse?

A volt meter or test light of some sort can work

 

[jfoj]

I would get the battery tested again, just because it is new, does not mean it is good.

The other thought is maybe something is going haywire with the anti theft system. If you tried Starting Fluid with no luck then it sounds like there is no spark. The anti theft systems are typically supposed to shut down spark and fuel pressure. Could be a problem with the anti theft module connections or a questionable relay inside the anti theft module?

Make sure your vehicle does not have any sort of aftermarket electronics, Lojack, or dealer installed anti theft device. Not sure if you know the full history of the vehicle and if purchased new. Sometimes dealers try to make money installed additonal tracking or anti theft devices.

If your vehicle fails to start, lock the vehicle and come back about 30 minutes later. Approach the driver side rear of the car and see if you hear the fuel pump power up when you hit the keyfob.

Just for kicks swap keyfobs and/or replace the keyfob battery.

Carry tools to disconnect the battery if the problem occurs again. Often you need to disconnect the battery on newer vehicles and either use a jumper cable or of the cables will reach, touch the cables together for 15-30 seconds to drain the capacitors in modules to try and do a reset to see what happens.

If the problem only happens after the vehicle has been running a while, chances are heat is causing a loose connection to break the electrical path. Often something like a crank sensor or maybe a cam sensor can cause the engine to randomly die and not restart because the crank sensor cannot properly determine the engine position. Watch the tach on the dash if there is a not start condition, you should see the engine RPM around 150-200 RPM while cranking, a scan tool can also monitor this.

You could think a questionable crank sensor should trigger a code or codes, but sometimes crazy things occur and you will not get a code because maybe the crank sensor detects the engine is turning, but cannot properly see the TDC indications and may not trigger a code. The only way you can see this typically is with a scope of some sort.

 

[sasso]

So verified spark and fuel.

If you are positive you have fuel delivery up to the injectors then the next thing is making sure the injectors are getting a signal to pulse

Are you able to disconnect an injector to see if it is getting a pulse?

A volt meter or test light of some sort can work

Yes, there is pulse

 

[blanchard7684]

Yes, there is pulse

Dang…

Fuel , spark, pulse, and I’m assuming no issue with throttle body ( air flow).

Every two hours of engine operation , a brake pedal and steering input makes it stop and can’t be restarted for extended period.

With no codes stored.

The ecm must be thinking everything is fine.

Either another control module or system is executing a shutdown command, or there is a major connector issue or a wire chafing issue or a wire connection problem.

Can you see if the issue is repeatable with only steering or only brake input?

Also… does this happen with both key fobs?

 

[sasso]

Dang…

Fuel , spark, pulse, and I’m assuming no issue with throttle body ( air flow).

Every two hours of engine operation , a brake pedal and steering input makes it stop and can’t be restarted for extended period.

With no codes stored.

The ecm must be thinking everything is fine.

Either another control module or system is executing a shutdown command, or there is a major connector issue or a wire chafing issue or a wire connection problem.

Can you see if the issue is repeatable with only steering or only brake input?

So, not 2 hours of operation, it turns of after 15 mins of operation, it idled for 2 hours without issue. Only when I put in brake input and steering input did it die. It felt like the load was too much for the car to handle and it turned off.

And then just refuses to start. Tomorrow morning I will try to get it to turn off with either steering input or brake input. But I am assuming it’s steering input because each time it turned off it was turned to the right.

But still what could cause it to not start up right away after it shuts down. Super confusing

 

[sasso]

I would get the battery tested again, just because it is new, does not mean it is good.

The other thought is maybe something is going haywire with the anti theft system. If you tried Starting Fluid with no luck then it sounds like there is no spark. The anti theft systems are typically supposed to shut down spark and fuel pressure. Could be a problem with the anti theft module connections or a questionable relay inside the anti theft module?

Make sure your vehicle does not have any sort of aftermarket electronics, Lojack, or dealer installed anti theft device. Not sure if you know the full history of the vehicle and if purchased new. Sometimes dealers try to make money installed additonal tracking or anti theft devices.

If your vehicle fails to start, lock the vehicle and come back about 30 minutes later. Approach the driver side rear of the car and see if you hear the fuel pump power up when you hit the keyfob.

Just for kicks swap keyfobs and/or replace the keyfob battery.

Carry tools to disconnect the battery if the problem occurs again. Often you need to disconnect the battery on newer vehicles and either use a jumper cable or of the cables will reach, touch the cables together for 15-30 seconds to drain the capacitors in modules to try and do a reset to see what happens.

If the problem only happens after the vehicle has been running a while, chances are heat is causing a loose connection to break the electrical path. Often something like a crank sensor or maybe a cam sensor can cause the engine to randomly die and not restart because the crank sensor cannot properly determine the engine position. Watch the tach on the dash if there is a not start condition, you should see the engine RPM around 150-200 RPM while cranking, a scan tool can also monitor this.

You could think a questionable crank sensor should trigger a code or codes, but sometimes crazy things occur and you will not get a code because maybe the crank sensor detects the engine is turning, but cannot properly see the TDC indications and may not trigger a code. The only way you can see this typically is with a scope of some sort.

Gonna try and replace the crank sensor and cam sensors tomorrow.

 

[tagexpcom]

To OP - Sorry you have this to deal with this, you have my sympathies. But very interesting! and thank you all ( OP and Posters) for sharing concise info and events! Following with high interest.

 

[Pressureangle]

Cuts off steering to the right.
Get it to cut off, then confirm the no-start
Steer it back to center with engine off, then try restart
May give a clue where to look

 

[Doubeleive]

I think that narrows it down to something physical then either in the ignition or engine
if the starter is spinning, has fuel and spark, all modules online then that would point me more towards something else on the engine
this is probably where you are going to have to go thru each thing on the engine and confirm with a meter
my next guess would maybe be a grounding point somewhere is failing under a load
when the no start occurs, it's going to take a step-by-step diagnostic a to b to c and confirm each thing is happening with a meter
somewhere there is a break happening, some tech might have to get on there with a oscilloscope

 

[blanchard7684]

So, not 2 hours of operation, it turns of after 15 mins of operation, it idled for 2 hours without issue. Only when I put in brake input and steering input did it die. It felt like the load was too much for the car to handle and it turned off.

And then just refuses to start. Tomorrow morning I will try to get it to turn off with either steering input or brake input. But I am assuming it’s steering input because each time it turned off it was turned to the right.

But still what could cause it to not start up right away after it shuts down. Super confusing

That almost sounds like the alternator was getting bogged down and the engine hit a stall point ( before the throttle could respond)

I had something very similar happen to a 2024 f150 work truck I use. I pulled into a parking area, turned the wheel sharply to position truck for reverse in, hit brake and it stalled.

I wonder if there might be a throttle issue— is it getting stuck out of position somehow not allowing a restart? And it may not be responding in time to keep engine above stall speed with a sudden increase in accessory load.

 

[Silverado4x4]

The motor should not boog down when steering as it has electric steering and not a power steering pump, if it's a cam or crank sensor it should have threw a code. Key start or push start, key start could be a wire in the column. I could see the alternator not putting out enough amps when turning the wheel and shutting down as said. Is there any mods to to vehicle?