Heres one for the late model Dodge/Cummins owners.

nctom

nctom

Well-Known Member
Joined
Dec 9, 2008
Location
CONCORD NC
Got a 2005 Dodge 2500 4x4 in the shop. it showed the codes for governor pressure solenoid and governor pressure sensor in a fresh Aamco reman trans. Also, it showed an intermittent low voltage drop. Long story short... When the ambient temp sensor in the intake kicks the block heater on, below 66 degrees F. The block heater draws 90 amps when they activate. Now, I probably don't need to tell you that 90 amps is a hell of a draw... Especially if your dual batts aren't up to the task! This guy has had 2 trannys replaced this year... All because his batteries were weak. When you hooked a meter up to the batteries and cycled the system, the volts would go from 12.5 down to 3 or 4 volts when the block heater cycled on, it would crank fine cause the heater is cut out during the cranking cycle. This low voltage situation toasted the sensor and the solenoid in the transmission.
 
Thanks for the info. So I know the "starting info" sticker on the sunvisor of my 2005 2500 says to rev it to 1000 rpm then let it idle for 30 seconds prior to driving. But with the info you just gave, perhaps 30 seconds isn't long enough if the block heater is still on. I had no idea the block heater pulled that much current.
 
nctom said:
Got a 2005 Dodge 2500 4x4 in the shop. it showed the codes for governor pressure solenoid and governor pressure sensor in a fresh Aamco reman trans. Also, it showed an intermittent low voltage drop. Long story short... When the ambient temp sensor in the intake kicks the block heater on, below 66 degrees F. The block heater draws 90 amps when they activate. Now, I probably don't need to tell you that 90 amps is a hell of a draw... Especially if your dual batts aren't up to the task! This guy has had 2 trannys replaced this year... All because his batteries were weak. When you hooked a meter up to the batteries and cycled the system, the volts would go from 12.5 down to 3 or 4 volts when the block heater cycled on, it would crank fine cause the heater is cut out during the cranking cycle. This low voltage situation toasted the sensor and the solenoid in the transmission.
Click to expand...
We see this alot. Newer vehicles and weak batteries don't go well together.
Not sure how it toasted the solenoid and sensor. We had one that had extreme voltage drops across the terminals to the grids. Fixed that and customer was upset that it now pulls the volt meter down after starting lol

Sent from my SCH-I605 using Tapatalk 2
 
The grid heater is no joke. Even with fresh group 65s, it'll drop below 12v.

Although, I'm not really sure what the point is.... I have never waited for the light, and mine starts fine, even when soaked in the teens for a few days.
 
I haven't ever had the grid heater in mine since I did the swap. Of course, it has a block heater in it as well. I've used it maybe once or twice and only when it was snowing and in the high teens. Other than that, mine will fire right up every time and its just a lowly VE pump motor.


I know they draw some serious juice though. It's basically like having a toaster in the intake :D
 
I hear ya' Mystery... Trans sensors really hate their amperage and voltage messed with. Its changed a lot over the years, nowadays I have to have a top notch drivability and diag guy in my trans shop. Lots of engine issues affect the trans performance these days.
 
nctom said:
I hear ya' Mystery... Trans sensors really hate their amperage and voltage messed with. Its changed a lot over the years, nowadays I have to have a top notch drivability and diag guy in my trans shop. Lots of engine issues affect the trans performance these days.
Click to expand...
The governor assembly is a pretty common failure with the re's. I would vote the two issues are of seperate origin. I could see the low voltage causing improper operation and codes but not a all out failure. However I'm sure if the great automakers of the US could determine anway to cause every part over $100 to fail due to a weak battery I'm pretty sure they would!


Sent from my SCH-I605 using Tapatalk 2
 
I agree with ya' on the codes being more common than as a cause of solenoid/sensor failure, but these were shot after 6 months on a fresh build. Could have been crappy parts, who knows? A set of Batts fixed it. The voltage regulator is built into the engine computer, so I know he was glad that wasn't the problem! Probably 2 grand for the PCM, plus a reflash and a roll back to get it to the dealer. Sheeeez!
 
They still have externally regulated alternators?! Damn...they've been doing that since the first gen trucks.
 
Back
Top