Engine dies while at highway speed

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Bubbaprice

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08 Ram 1500 4.7l

Lately the engine will die while at highway speeds/rpms under load. It's an immediate shut off, no shakes shudders. Afterwards it will start right up and goes into limp mode, no cruise control, engine light blinks and dings. When I disconnect and reconnect the battery all is well and lasts a couple days.

I've checked for codes but there aren't any. It happens usually once every couple days.

I've had to do a bit of maintenance and repair over the last 6 months and wonder if maybe I got bad parts or did the job wrong.

New Starter, Battery, O2 sensors, MAP sensor, Fuel pump, spark plugs, one new coil.

Cleaned Throttle body
 

Oliver Closehauf

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I don't know what your problem is, but I've had that problem before on other cars where the hall sensor on the distributor was on its way out.
Maybe there is a crank or cam sensor starting to go.
 

KoboldTaco

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I don't know what your problem is, but I've had that problem before on other cars where the hall sensor on the distributor was on its way out.
Maybe there is a crank or cam sensor starting to go.
I need a better crystal ball. Without codes - yikes. I suppose for the fun ones like this I am thankful for professional mechanics!
 

JohnnyMac

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The only thing on your list of new parts that I would think would cause an instant shut down would be the fuel pump, but I don't think it would cause the truck to go into limp mode. Also, have you actually scanned for the codes or are you just assuming that because the CEL didn't come on there are no codes? I've seen some posts about the ignition switch contacts being dirty and just shutting off the truck, but again, not sure why it would go into limp mode. It would make sense that you get no codes because of that though. Does the truck go dark, meaning do you lose dash lights/gauges/radio or is it just the engine dying. This would eliminate a bad battery connection although a bad connection to the ECU might cause a hiccup so check those connections.
 
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Bubbaprice

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The dash goes dark. I've checked positive and negative cables but they are clean and seem to be making good contact. I will take a look at the ECU connector.

Another thought came to me, I have an after market auto start on the truck, that when you hit the brake, shift to gear without the key, it also acts like this.
 

crash68

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Another thought came to me, I have an after market auto start on the truck, that when you hit the brake, shift to
I would check all the wiring connectors related to the remote start, also try unplugging it from the CANbus. Aftermarket accessories can problems on the CANbus.
 
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Bubbaprice

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The only thing on your list of new parts that I would think would cause an instant shut down would be the fuel pump, but I don't think it would cause the truck to go into limp mode. Also, have you actually scanned for the codes or are you just assuming that because the CEL didn't come on there are no codes? I've seen some posts about the ignition switch contacts being dirty and just shutting off the truck, but again, not sure why it would go into limp mode. It would make sense that you get no codes because of that though. Does the truck go dark, meaning do you lose dash lights/gauges/radio or is it just the engine dying. This would eliminate a bad battery connection although a bad connection to the ECU might cause a hiccup so check those connections.
I had my phone attached to the wireless ob2 reader and was watching my truck info while this has happened. After I fired it back up and found a spot to pull over I scanned for codes and it had nothing on it.
 
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