96 vette Transmission Problem code P1860
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 16
Likes: 0
96 vette Transmission Problem code P1860
There is a slight pump whine/howl at idle in park/neutral. But a Actron OBDII scanner only show a code P1860 (Manufacturer Controlled Transmission), and doesn’t give me any other details in what wrong with the trans. Please tell me what is really wrong with my transmission, and how to fix it. Thank you very much!
Pro
Joined: Jun 2008
Posts: 610
Likes: 1
PWM is the type of solenoid. Pulse width modulated, as opposed to a simple on/off. It works similar to a fuel injector. Allows controlling the fluid pressure.
Your code is a failure somewhere in the circuit which might be the solenoid, a broken wire, or possibly a blown fuse. The solenoid is fed power all the time and grounded to activate it. First thing to do is verify that you do or do not have power to the PWM solenoid. You would do this (with the key turned on) at the large connector that plugs into the passenger side of the transmission. I think there should be 12v on two of the pins, but I don't know which is which. Perhaps someone else can expand on this.
Your code is a failure somewhere in the circuit which might be the solenoid, a broken wire, or possibly a blown fuse. The solenoid is fed power all the time and grounded to activate it. First thing to do is verify that you do or do not have power to the PWM solenoid. You would do this (with the key turned on) at the large connector that plugs into the passenger side of the transmission. I think there should be 12v on two of the pins, but I don't know which is which. Perhaps someone else can expand on this.
Safety Car
Joined: Jun 2006
Posts: 3,629
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From: FL
Drifting
Joined: Jul 2007
Posts: 1,294
Likes: 37
I used to have the same code. I seems to occur when there a difference between the converter rpm and the output shaft rpm if I remember correctly. I would get this code after WOT 3/4 shifts.
I did an internet search on this code and found out that it is extremely common in the 4l60e transmission. There is a defect of some sort, and many fixes for it.
Unfortunately for me, I've noticed that after I rebuilt my transmission, the code went away. My 3/4 pack was slipping. Don't know if that is the case for you.
I did an internet search on this code and found out that it is extremely common in the 4l60e transmission. There is a defect of some sort, and many fixes for it.
Unfortunately for me, I've noticed that after I rebuilt my transmission, the code went away. My 3/4 pack was slipping. Don't know if that is the case for you.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
Sounds like a wiring problem!
There are two solenoids. 1.TCC PWM Solenoid 2. TCC Solenoid Valve
They are both supplied 12 v continuously thru the AUTO TRANS 15A fuse in the IP fuse block.
The PCM grounds them to activate them.
The 12v is pink. the PWM ground is BRN.. The TCC is TAN/BLK.
Conditions for setting DTC:
*No system voltage DTC P0560
*No 2-3 shift solenoid DTCs P0756 or P0758
*No 1-2 shift solenoid DTCs P0751 or P0753
*The ignition is on
*First gear commanded
*The PCM commands the solenoid to 0% and the voltage remains high
*All conditions met for 5 secs
DTC P1860 detects a continuous open or a short to ground in the TCC PWM circuit or the TCC PWM Solenoid Valve.
There are two solenoids. 1.TCC PWM Solenoid 2. TCC Solenoid Valve
They are both supplied 12 v continuously thru the AUTO TRANS 15A fuse in the IP fuse block.
The PCM grounds them to activate them.
The 12v is pink. the PWM ground is BRN.. The TCC is TAN/BLK.
Conditions for setting DTC:
*No system voltage DTC P0560
*No 2-3 shift solenoid DTCs P0756 or P0758
*No 1-2 shift solenoid DTCs P0751 or P0753
*The ignition is on
*First gear commanded
*The PCM commands the solenoid to 0% and the voltage remains high
*All conditions met for 5 secs
DTC P1860 detects a continuous open or a short to ground in the TCC PWM circuit or the TCC PWM Solenoid Valve.
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