P0722 on GMC: How to Diagnose & Fix
Output Speed Sensor Circuit No Signal
1 GMC model · 1 documented issue · 1 critical · $500-$3,500 repair
P0722 on GMC by model: symptoms, diagnosis and fix
The Allison 1000 transmission paired with the Duramax diesel in 2008-2015 Sierra 3500HD trucks has a high failure rate for the Transmission Control Module (TCM). A class action suit was filed covering these years. Additional issues include input/output speed sensor failures causing no-forward/reverse conditions, and certain 2012 trucks built with incorrect thrust bearings.
Common Symptoms
- Intermittent no forward or reverse movement
- Flashing PRNDL display
- Range Shift Inhibited message
- Harsh or delayed shifts
- Transmission noise or whine
- Check engine light with transmission codes
How to Fix
Sources for this issue (1)
P0722 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0722 mean on a GMC?
P0722 stands for "Output Speed Sensor Circuit No Signal." This code means the transmission control module is receiving no signal at all from the output speed sensor, which measures how fast the transmission's output shaft (and therefore the vehicle) is turning. The computer relies on this sensor to time gear shifts, control the torque converter, and confirm road speed, so when the signal drops out it suspects a broken circuit or dead sensor. You may notice harsh or erratic shifting, the transmission staying in one gear, or an inaccurate or dead speedometer. It is an electrical/no-signal fault rather than just an out-of-range reading. On GMC it is documented across 1 model: Sierra 3500HD.
What are the most common causes of P0722?
The most common causes of P0722 are: Failed output (vehicle) speed sensor, Broken, corroded, or loose sensor wiring or connector, Open or shorted circuit between sensor and TCM, Damaged sensor reluctor/tone ring on the output shaft, Metal debris or contamination on the sensor tip, Poor ground or power supply to the sensor, Faulty transmission control module (less common). The specific cause varies by vehicle.
How much does it cost to fix P0722 on a GMC?
Published repair estimates on GMC range from $500 to $3,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0722 on a different make?
View P0722 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.