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Pulling out of the grocery store parking space today, trans shuddering badly and thus illuminating the check engine light. OnStar diagnostics produced P0700 and P1962 which i believe is the real culprit. I idle creep disabled too as I was getting it moved into the garage until Monday when the dealer opens for service.
any help for background with either/both codes will be most appreciated. Google search is not producing very much at all. It’s a 2025 Stingray 2LT with 4400 miles. It has been flawless up to this point. Thanks for any and all help and taking the time to read all this.
Unfortunately this is driving in a straight line initially and also minor turns. But I do know what you mention as I experienced that with my off road racers.
Unfortunately this is driving in a straight line initially and also minor turns. But I do know what you mention as I experienced that with my off road racers.
I've had P0700 codes get thrown while on the track. Cleared and no issue. The other code is more serious. Could be a hard failure in a solenoid or other component. It'll get fixed under warranty.
GM codes P0700 and P1962 together
indicate a severe transmission control system fault, specifically pointing to a failed transmission vane pump (or related hydraulic pressure failure) on GM vehicles. P0700 is a general request for the check engine light due to a Transmission Control Module (TCM) error, while P1962 indicates the pump is not providing proper pressure.
P0700 is simply informational - it instructs the car to turn on the MIL (aka CEL). I looked up the P1962 in the version of the C8 Service Manual that I have. Procedures can change, but here are the highlights I found - and it includes a step you might be able to perform if you have scan tool - also the code will clear after a few ignition cycles if the condition that caused it goes away. Notice in green are some steps that you can do. But if the code comes back and there are no other codes, it goes straight to a transmission replacement. And this is where the procedure may have been updated - I don't have the latest information - but now GM allows some component replacments that were not previously allowed.
DTC Descriptor (I think the second one Odd Gear Clutch applies to the code you have)
Odd Gear Clutch Safety Performance 1
Odd Gear Clutch Safety Performance 2
Verify there are no DTCs set related to the following system/component (you only report having one code (other than the p0700 so you have no other codes set)
If a related DTC is not set 6. Ignition/Vehicle >> Off
7. Scan Tool >> Disconnect
8. Driver Door >> Open and close the door.
9. Wait 60 s before proceeding to the next step.
10. Clear the DTCs.
11. Ignition/Vehicle >> Off
12. Scan Tool >> Disconnect
13. Driver Door >> Open and close the door.
14. Wait 60 s before proceeding to the next step.
15. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed
from the Freeze Frame/Failure Records data.
16. Verify the DTC does not set. 17.
If only DTC P1960, P1962
Replace the component: T12 Automatic Transmission
Last edited by Vetteman Jack; Feb 6, 2026 at 07:03 AM.
Andy, would you agree that step-10 infers that the ignition is on, not running, need to run scan tool?
This is step-11 states to set ignition Off.
Step-6 insures the ignition if Off. Previous steps may have it On.
Thanks Andy for providing all this technical info we don't have access to!
Thank you, Bill this is the info I can greatly use when bringing in the vehicle to the dealer tomorrow. And thank you, Andy also for your info also. No scan tool here. Looks like it’s best to have it towed to the dealer and not chance driving it there. Dang it.
What are the chances??? Was talking to my wife about the above info using a scan tool which I don’t have and she then proceeds to go upstairs and bring one down to me! Sh said it was for my birthday next Monday but maybe you can us it today! Haha. Will give it a try shortly, a Creador Elite G.
Andy, would you agree that step-10 infers that the ignition is on, not running, need to run scan tool?
This is step-11 states to set ignition Off.
Step-6 insures the ignition if Off. Previous steps may have it On.
Thanks Andy for providing all this technical info we don't have access to!
I'm not certain, but if the ignition needs to be on clear the DTC with the scan tool, then yes. That next step with the door open and shut sounds like the reset procedure we often see on the forum. But its a little different, saying open then shut the door and wait 60 seconds.
Attached is what my service manual (Chilton's) says for this DTC, as well as the procedure it states to follow if the code continues to reappear.
It instructs to replace the valvebody though, not the clutch assembly.
Does your Chilton's manual have a clutch replacement or clutch component replacement procedure in it? I think the clutch related repair procedures, and availability of the parts necessary to do so is relatively recent development - may within the last year or so. The GM on line manuals are updated as needed fro all model years - I don't know how the Chilton's manual works.
Attached is what my service manual (Chilton's) says for this DTC, as well as the procedure it states to follow if the code continues to reappear.
It instructs to replace the valvebody though, not the clutch assembly.
That Transmission Service Diagnostic Test procedure from Chiltons that you posted matches the "Transmission Service Fast Lean Procedure" in the version of the manual that I have. Mine is old and not updated. But there is an interesting and important statement in your version about how "The transmission will continue to adapt during continued vehicle usage". I believe this is referring to adapting the initial clutch pressure apply pressures. I think as the clutches wear or change, the car will adapt to maintain smooth shifts.
Does your Chilton's manual have a clutch replacement or clutch component replacement procedure in it? I think the clutch related repair procedures, and availability of the parts necessary to do so is relatively recent development - may within the last year or so. The GM on line manuals are updated as needed fro all model years - I don't know how the Chilton's manual works.
Yes, the 2022 Chiltons does have a "Direct Clutch Replacement" procedure (see attached PDF).
Here are all the R&R procedures available in the Chiltons for the trans:
Yes, the 2022 Chiltons does have a "Direct Clutch Replacement" procedure (see attached PDF).
Here are all the R&R procedures available in the Chiltons for the trans:
Thanks! That is interesting. There is also a procedure and parts for dealing with park lock pawl issues, including the dreaded park pawl sensor drift issue, which previously required replacement of the transmission.
Folks have speculated about the reason internal repairs were not originally included in the diagnostic procedures. One thought being that GM/Tremec wanted the transmissions back for analysis. With repair procedures and parts being dribbled out as they determined the failure conditions and possible repairs. But its clear (and I suppose obvious) that parts availability is major factor as well. They have to be able to supply internal transmission components needed for the repairs.