Source for a Transfer Case Encoder Motor

My 99 Tahoe (NP8 TC) is stuck in 4 wheel low and the service 4 wheel drive light is on. After some searching on here, I figured it was the encoder motor.

I took it to a shop and had the codes pulled, they report a DTC C0327. So now I am looking for a replacement encoder motor (part #12474401) -

I see there are GM original (gmpartsdirect, dealer), re-manufactured ones, and it appears some are "new" off-brand on the web.

Any thoughts on what to buy? I don't mind spending the money if its a matter of quality and/or reliability, but don't like getting soaked either....

Thanks -

My 99 Tahoe (NP8 TC) is stuck in 4 wheel low and the service 4 wheel drive light is on. After some searching on here, I figured it was the encoder motor.

I took it to a shop and had the codes pulled, they report a DTC C0327. So now I am looking for a replacement encoder motor (part #12474401) -

I see there are GM original (gmpartsdirect, dealer), re-manufactured ones, and it appears some are "new" off-brand on the web.

Any thoughts on what to buy? I don't mind spending the money if its a matter of quality and/or reliability, but don't like getting soaked either....

Thanks -

I would go with a new encoder motor...one of the failures with these is current leakage.. a used one will not last long..if you do off roading in 4x4 low often you must remember to replace the transfercase fluid whenever it gets gray/black...should be blue color..

I was thinking the same thing... I have had a rash of bad luck getting parts from the discount autoplaces (cv joints etc) where they just don't seem to last very long..

Code does not say replace the part.
It needs more tested out .
Could be encoder motor or ATC control, module or wiring.


Depending on what the problem is.
Some repair shops are repairing /replacing a resister in the encoder motors.
Good luck
MT

Code does not say replace the part.
It needs more tested out .
Could be encoder motor or ATC control, module or wiring.


Depending on what the problem is.
Some repair shops are repairing /replacing a resister in the encoder motors.
Good luck
MT



ya the dtc does not say replace motor but the fact is this code 90% of the time is motor current is excessive or zero........it could also mean his tranfercase is causing the encoder motor problem as well as the wiring...to it

May be only 10% it is not it but thst 10% can bite you in the rear real bad.
Proper testing first solves a lot of problems.
MT

May be only 10% it is not it but thst 10% can bite you in the rear real bad.
Proper testing first solves a lot of problems.
MT

i agree but to test/verify motor is the only problem it will be removed..then upon inspecting it will be replaced or troubleshoot further...


the motor in hand when this is done is very helpful and if the motor is good then return unused in box....for credit for what you may need..


this also will get vehicle on road faster with less hassle...



this motor if 10years old I would bet it is bad...but I believe that lack of transfer case fluid changes damages these motors as the lubricity of the fluid is reduced....

Thanks for your help MT-2500 and j cAT, got it all fixed. I printed out the diagnostic chart from alldatadiy.com and started going through it. I was getting between 7 - 9 volts across terminal E & A on connector C1; and around 5 volts across terminals F, B, D, and C to A on connector C1. At that point, everything said to replace the encoder motor.

After some price checking and research, I ended up getting the motor from NAPA, brand new, Limited Lifetime Warranty for like $279 I think. Its cheaper than a re-manufactured one (that has a 90 day warranty) and if I have problems, its a simple fix. Not sure what the warranty is from the dealer tho.

Put the new motor in tonight and it works like a champ. On a side note, I also replaced the dash switch since the LED's were not working and figured it was worth the chance... switch works, LEDs stay on, shifts in and out of 2HI / 4HI etc...

Thanks again for all your help.

You are welcome and thanks for posting back how it went.
Glad all is well and shifting good.
MT

Thanks for your help MT-2500 and j cAT, got it all fixed. I printed out the diagnostic chart from alldatadiy.com and started going through it. I was getting between 7 - 9 volts across terminal E & A on connector C1; and around 5 volts across terminals F, B, D, and C to A on connector C1. At that point, everything said to replace the encoder motor.

After some price checking and research, I ended up getting the motor from NAPA, brand new, Limited Lifetime Warranty for like $279 I think. Its cheaper than a re-manufactured one (that has a 90 day warranty) and if I have problems, its a simple fix. Not sure what the warranty is from the dealer tho.

Put the new motor in tonight and it works like a champ. On a side note, I also replaced the dash switch since the LED's were not working and figured it was worth the chance... switch works, LEDs stay on, shifts in and out of 2HI / 4HI etc...

Thanks again for all your help.

thanks for that NAPA part supplier and this warrantee you got is the best!!!