gw ellis

2017 Ram w/5.9 Cummins
Here is my story, I first installed 2 brand new batteries mid winter. I then had injectors put in truck last winter at 190,000 miles because of hard starting. This fixed the hard starting. New problem that took awhile for me to recognize the grid heater was causing. Immediately after installing the injectors and valve cover gasket (same day) when the grid heater is cycling and I am starting from a stop or shifting from second to 3rd (6 speed manual) the engine goes into a safe mode misfire for exactly 10 seconds then resumes normal operation. This only happens when grid heater is firing and is the exact duration each time. This does not happen during the summer months when grid heater is not cycling. Fault is P2149. P2149 Fuel Injector Group 2 Supply Voltage Circuit. I have double checked the connections at the injectors and valve cover gasket time and time again. This voltage problem is 100% being caused by the voltage drop when the grid fires. Any help would be greatly appreciated. Grant.

gw ellis

Has no one else seen this problem?

Dean Snow

I have had exactly this happen. Drops on three cylinders. Will start to smoke white. Go away randomly after I clear codes. I spent hours checking wiring ect. Testing till I was blue in the face and bloody hands. I’ve seen this caused before by bad batteries yet my were still “decent”. It was my alternator in this case. The actual amperage and voltage was diving way low for the ECU sensing. Voltage in truck couldn’t really keep up with this. My scenario was exactly like yours to a T. Replaced alternator with mean green alternator.

Put extra 0 gauge wiring at the same time from the alternator mounting bolt to battery ground. Cleaned all metal with sandpaper including the factory that mounts grounds over paint! Then the Battery ground to chassis. On both sides on each battery. Also ran an extra cross over cable from positive battery to battery on each side. And replaced the alternator to battery wire with 2 zero gauge wires and a single 250 amp fuse. This was the recommended upgrades for the mean green alternator. I also run a 4500rms watt subwoofer system in the back and I couldn’t be happier that the problem is gone and the electrical system works so much better for my needs. I replaced with a denso reman by Delco remy 220 amp alternator off of the newer trucks the first time and I had two replacements go bad both direct short to ground. The original was a 136 amp so it was a nice bump. The new is a custom 320 amp alternator and works flawless. I

for a free start id pull all terminals going to chassis and frame and clean them with emery paper and a wire brush first. Including where the alternator mounts to the engine. Mine was corroded and had rust in the mounts. There was no areas of nice contact.

BigIron70

Last year for a 5.9 was 2007 not 2017, If you have a 2017 then it is a 6.7 and still under warranty. Your signature is 2007 so I assume that is the correct year. I have seen this code many times but problem was not caused by grid heaters. Problem was failing injector, injector wiring harness or PCM. You could have a failing PCM or you could have power or ground issues with the PCM. If no other codes are setting such as low voltage codes and PCM has good grounds and power and you ohm tested all injectors and wiring harness and those tested good then I would suspect PCM issue.

gw ellis

Dean, Thanks for the info. After new injector install and new batteries it does seem to pull a little lower. I will start by cleaning all connections. Grant.

gw ellis

Dean, I did everything suggested including a new alternator with no luck. Does anyone have any other suggestions? Again, I only get the code and 10 second shutdown on 3 cylinders when the grid heater activates. Thank You, Grant.