Diagnostic article Generic OBD-II
P2817: GR10 torque-converter clutch fails to achieve commanded coupling
P2817 evaluates excessive torque-converter slip while the GR10 controller requests lock or controlled-slip operation.
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Documented application
2025 GM 25OBDG04B diagnostic parameter file; the cited monitor is documented, but individual vehicle, engine and calibration applicability has not been established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P2817 is pressure-control solenoid H performance/stuck off. In this 25OBDG04B GR10 entry, H controls the torque-converter clutch. The monitor detects a hydraulic failure to achieve commanded coupling, rather than an electrical open circuit.
Lock and controlled slip are different comparisons
In lock mode, converter slip is engine speed minus transmission input speed; the documented failure boundary is above 130 rpm. In controlled-slip mode, the controller instead compares actual slip with commanded slip and uses a calibrated error threshold. Applying the lock-mode number to all controlled-slip operation would misread the strategy.
A qualified failure must last more than four seconds before incrementing the counter, which must exceed three. The update rate is 25 ms and reporting Type A, one trip. Commanded pressure above 500 kPa for more than two seconds, available hydraulic pressure, suitable operating conditions and valid speed signals are among the gates.
Useful interpretation
Record TCC mode, target slip, actual slip and pressure command together. Slip can be intentional in controlled-slip mode, so its mere presence does not prove a stuck-off valve. Electrical and speed-sensor faults can invalidate this hydraulic assessment.
Verification requires the appropriate qualified coupling test through the service procedure. The summary does not prove whether the ultimate problem is the control valve, converter or another hydraulic component, and its GR10 mapping must not be generalized to another controller.
Source and application limits
This explanation covers the cited 2025 GM monitor. Confirm the vehicle and calibration in its service information before applying these limits; inclusion in this file does not establish model compatibility. GM diagnostic parameters, PDF page 2289. GM diagnostic parameters, PDF page 2290.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Pressure Control Solenoid H Performance/Stuck Off
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT