Will not start, will not shift and the brakes are locked, codes P025A and U0109?

BLACKIE3264

MEMBER
2017 RAM 1500
5.7L
V8
4WD
AUTOMATIC
97,000 MILES

Hi all,

I had my truck parked for 8 nights at the airport and when I returned it would not start. Sounds like the starter was engaging but appears to have no fuel supply. Tried jumping the battery and still no luck. Checked battery voltage and it was fine.

When the tow truck showed up to bring it to a shop, the truck would not shift. Tried manual override to get the truck into neutral and that did not work. It looked like the back wheels were still locked - when attempting to pull out of parking spot it would drag.

Shop ram code reader and it spit out - P025A and U0109.

Shop tech diagnosed and appeared that it was a fuel pump control module - it received signal from PCM but did not send to fuel pump. Tech jumpered power to fuel pump and it sounded like it was running according to tech.

Once they replaced the fuel pump control module, the problem was still there - cranks but no ignition.

Any help with diagnosis - both for ignition problem and shifting problem?
Thank you

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,640 POSTS

It sounds like we lost power or ground to the FPCM (fuel pump control module). Here are the fuses and relays that run the system with the FPCM ground location so you can check that as well.

P025A - Fuel Pump Control Module Circuit/Open.
U0109 - Lost Communication with Fuel Pump Control Module.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

OPERATION
When the Powertrain Control Module (PCM) receives a � Start’ or � Run’ signal from the ignition; It energizes the Fuel Pump relay which sends a continuous 12-volt supply to the Fuel Pump Control Module (FPCM). The PCM also sends a control signal directly to the FPCM which regulates the Pulse Width Modulated (PWM) signal that will be sent to the Fuel Pump Module. The PWM signal (duty cycle) will vary from 10-100% depending on the input of the Fuel Rail Pressure sensor and other engine demands. The PCM receives a PWM signal from the FPCM representing the state of all inputs and outputs of the FPCM. This is a Constant Pressure Fuel system which means any Delta Pressure test performed on the Fuel Pump would show a continuous pressure (regardless of the changes in PWM). If a pressure sensor fails or other failures are present; The duty cycle goes to Limp mode (100%) to maintain fuel pressure.

This is what was replaced correct? Check out the images (below). Please let us know what happens.

Images (Click to make bigger)

Will not start, will not shift and the brakes are locked, codes P025A and U0109?

1 Reply

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