P0722 on 2014-2020 Chevrolet Malibu: Output Speed Sensor Causes and Fixes

What's Unique About the 2014-2020 Chevrolet Malibu

The key challenge with the 2014-2020 Malibu is that for its most common transmissions (like the 6-speed 6T40/6T45 and the 9-speed 9T50), the Output Speed Sensor is not an easily accessible external part. Instead, it is located inside the transmission housing, underneath the valve body. This turns a simple sensor swap into a more complex and labor-intensive job. General Motors has issued Technical Service Bulletin #17-NA-147 that addresses this code. For vehicles built before March 2, 2017, the TSB recommends replacing both the output speed sensor and the internal transmission wiring harness, acknowledging a known pattern of failure. For vehicles built after that date, only the sensor replacement is typically required.

Generation note: This range covers two Malibu generations: - 8th Generation (2014-2016): Includes the 'Malibu Limited' in 2016. These models primarily use the 6-speed 6T40/6T45 automatic transmission, where the OSS is internal. - 9th Generation (2016-2020): These models came with several different transmissions, including a 6-speed (6T40), a CVT, and a 9-speed automatic (9T50). On both the 6-speed and 9-speed, the sensor is internal. It is critical to identify the specific transmission in your vehicle, as the part location and repair procedure depend on it.

Symptoms You May Notice

• Harsh, erratic, or delayed gear shifts.
• Transmission is stuck in a single gear (fail-safe or 'limp' mode).
• Check Engine Light is illuminated.
• Speedometer may work erratically or not at all.
• Cruise control will not engage.
• Reduced fuel economy.
• Vehicle may hesitate or feel sluggish during acceleration.

Most Likely Causes

1. Faulty Internal Output Speed Sensor (OSS) 🔴 High Probability The sensor is located inside the transmission, exposed to heat and potentially contaminated fluid over its service life. GM has issued TSBs related to this sensor's failure, confirming it's a known issue.
   How to confirm: A professional technician will use a scan tool to monitor live data from the OSS. If the reading is zero while the vehicle is moving, and the wiring is confirmed to be good, the sensor has failed.
   Typical fix: Replace the Output Speed Sensor. This requires draining the transmission fluid, removing the pan, and removing the valve body to access the sensor.
   Est. part cost: $25-$60
2. Damaged Wiring or Connectors 🟡 Medium Probability This can include the external harness leading to the transmission or, more specifically for this platform, the internal transmission wiring harness that connects to the sensor. TSB 17-NA-147 specifically calls for replacing this internal harness on earlier models.
   How to confirm: Inspect the external wiring for any visible damage. Test for continuity and voltage at the connector. The internal harness must be inspected after removing the transmission pan and valve body. A multimeter can be used to check for opens or shorts in the circuit.
   Typical fix: Repair the damaged section of the wiring harness or replace the connector. In many cases, especially on pre-2017 models, the entire internal transmission harness is replaced along with the sensor as a kit (Part #24292335).
   Est. part cost: $50-$150 for the harness kit
3. Low or Contaminated Transmission Fluid ⚪ Low Probability While not specific to the Malibu, any transmission can suffer from low fluid due to leaks. Old, degraded fluid can also contain metallic shavings that may stick to the magnetic sensor tip and interfere with its signal.
   How to confirm: Check the transmission fluid level and condition. On many of these models, there is no dipstick, so it must be checked via a fill plug on the side of the transmission case. If the fluid is dark, burnt-smelling, or contains metallic particles, it indicates a problem.
   Typical fix: Address the source of any leaks. Perform a transmission fluid and filter change. If significant metal is present, further internal inspection is needed.
   Est. part cost: $100-$250 for a fluid/filter service
4. Faulty Transmission Control Module (TCM) ⚪ Low Probability
   How to confirm: This is typically diagnosed last. If the sensor, wiring, and fluid are all confirmed to be good, the TCM is the likely culprit. This requires advanced diagnostics, and sometimes a software update or re-flash can resolve the issue.
   Typical fix: Replace and program the Transmission Control Module. Some TCM issues can be resolved with a software update from a GM dealer.
   Est. part cost: $600-$900 for a programmed module

Diagnosis Steps

1. Check for other stored DTCs. P0700 will likely be present, but look for others like P0717 or P0721.
2. Check the transmission fluid level and condition. This may require raising the vehicle and removing a check/fill plug. Note any signs of burning or metal debris.
3. Using an advanced scan tool, monitor the live data for the Output Speed Sensor while driving. The reading should increase smoothly with vehicle speed. A constant reading of 0 RPM indicates a problem.
4. Visually inspect the external transmission wiring harness and connectors for any signs of damage, corrosion, or looseness.
5. If external wiring is okay and the sensor signal is absent, the next step is internal inspection. This involves draining the fluid and removing the transmission pan and valve body.
6. Once inside, inspect the internal wiring harness for breaks, chafing, or brittle wires, especially near the sensor connector.
7. Test the Output Speed Sensor itself for proper resistance according to factory specifications. If the sensor and wiring test good, the issue may be with the Transmission Control Module (TCM).

Parts You'll Likely Need

• Automatic Transmission Output Speed Sensor (OEM #24276628) — This is the sensor that fails and directly causes the P0722 code. The part number 24276628 is for the common 6T40/6T45 transmission. Note that TSB 17-NA-147 lists a different part number (24289782) for post-March 2017 vehicles.
  Trusted brands: ACDelco (GM Genuine), Dorman, NGK/NTK
  OEM price range: $40-$60
  Aftermarket price range: $25-$45
• Internal Transmission Wiring Harness Kit (OEM #24292335) — TSB 17-NA-147 recommends replacing the internal harness along with the sensor on vehicles built before March 2, 2017. This kit includes the harness and the updated sensor.
  Trusted brands: ACDelco (GM Genuine)
  OEM price range: $100-$150
• Transmission Fluid (OEM #19418470 (ACDelco DEXRON-VI)) — The transmission must be drained to access the internal sensor. It must be refilled with the correct type of fluid. 6-speed and 9-speed automatics in this Malibu generation typically require DEXRON-VI.
  Trusted brands: ACDelco, Valvoline, Castrol
  OEM price range: $10-$15 per quart
  Aftermarket price range: $8-$12 per quart
• Transmission Oil Pan Gasket — The oil pan must be removed, and the gasket should always be replaced to prevent leaks. Some pans use RTV sealant instead of a pre-formed gasket.
  Trusted brands: ACDelco, Fel-Pro
  OEM price range: $20-$40
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• P0700 — P0700 is a generic code indicating that the Transmission Control Module 🎬 Watch this guide on replacing the output shaft speed sensor (TCM) has stored a fault. It almost always appears alongside a more specific transmission code like P0722.
• P0717 — This code is for 'Input Speed Sensor No Signal'. It is often listed in the same TSBs as P0722 (like TSB 17-NA-147 and PIP5473), suggesting a common failure pattern in the transmission's speed sensor circuits or internal wiring harness.
• P0721 — This code for 'Output Speed Sensor Range/Performance' can be a precursor to or appear with P0722, indicating the sensor's signal is becoming erratic or intermittent before failing completely.

Technical Service Bulletins (TSBs) & Recalls

• 17-NA-147
• PIP5473

Platform-Specific Known Issues

• A known issue documented in GM TSB #17-NA-147 addresses a cluster of codes including P0722. If initial diagnostics find no obvious cause, the bulletin advises replacing the output speed sensor and, on vehicles built before March 2, 2017, the internal transmission wiring harness as well.

Mechanic-Grade Diagnostic Values

• Output Speed Sensor Signal (Hall Effect) — expected: A regular square wave, typically 2-5V amplitude, with frequency increasing with speed.. Failure: Absence of a waveform when the transmission output shaft is rotating.
• Ground Circuit Resistance — expected: Less than 5 Ω.. Failure: A reading higher than 5 Ω indicates a poor ground connection, which can cause sensor signal issues.

Scan Tool Commands That Help

• GDS2 (GM Dealer Scan Tool) or equivalent high-level scanner: Transmission Service Fast Learn / Reset Transmission Adapts — After replacing the output speed sensor, internal harness, or valve body, this procedure should be performed to reset and relearn the transmission's adaptive shift data. Skipping this can result in continued poor shift quality even after the hardware is fixed.

Wiring & Ground Locations

• G104 — On older models, described as the left front corner of the engine compartment or left side of the engine compartment. On some 3.6L engines, it's on the back side of the engine. A poor engine ground can cause a variety of sensor issues.. The TCM and its sensors rely on clean ground connections. A faulty G104, which is a primary engine ground, can introduce electrical noise or voltage offsets that may disrupt the output speed sensor signal, even if the sensor and its direct wiring are intact.
• Transmission Control Module (TCM) Fuses — In the under-hood fuse box on the driver's side for the 2016-2020 generation. Specifically, fuses F15 (5A), F26 (15A), and potentially F57.. A blown fuse will cut power to the TCM, which processes the signal from the output speed sensor. This would cause a P0722 along with other transmission-related codes.
• Engine Harness Chafe Point — Check the engine harness for potential contact with the Left Front Upper Control Arm Bushing bracket.. Normal engine movement can cause the harness to rub against brackets, eventually wearing through the insulation and causing a short or open circuit. This could affect the wires running from the transmission to the TCM/ECM, directly causing a 'No Signal' code like P0722.

Real Owner Repair Stories

• 2CarPros.com user 'UZO176' (2019 Chevrolet Malibu LT with 9-speed automatic transmission) — Check Engine Light with code P0722.
  ❌ Tried (didn't work) Initially confused the part provided by an auto parts store (likely an external sensor) with the actual internal sensor.
  ✅ What actually fixed it The user was correctly advised that the output speed sensor was located inside the transmission, under the valve body. The fix required removing the transmission pan and valve body to access and replace the correct sensor.

OEM Part Supersession History

• 24276628 (and others it replaced, like 24275800, 24259852) → 24289782 (for vehicles built AFTER 03/02/2017) — Part design update by GM to improve reliability, as documented in TSB 17-NA-147.
  Heads up: For vehicles built ON OR BEFORE 03/02/2017, the recommended repair is to use kit #24292335, which includes an updated sensor AND a new internal wiring harness. Using just the sensor may not resolve the issue on these earlier models.

Model Year Variations Within This Range

• 2014 - Early 2017 (built on or before March 2, 2017): Per TSB 17-NA-147, the recommended fix for P0722 (if no other cause is found) is to replace both the output speed sensor and the internal transmission wiring harness using kit #24292335.
• Late 2017 - 2020 (built after March 2, 2017): Per TSB 17-NA-147, the recommended fix for P0722 (if no other cause is found) is to replace only the output speed sensor with the updated part #24289782.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Cracked Pistons (1.5L Turbo LFV Engine) 🔴 High — Common on 2016-2018 models, often occurring between 30,000 and 80,000 miles. Can cause loss of compression, misfires, and reduced power. (Ref: Multiple TSBs exist, including some related to pre-ignition which can contribute to this failure.)
• 'Shift to Park' Message 🟠 Medium — Widespread on 2016-2018 models. The car fails to recognize it's in Park, preventing it from shutting off. (Ref: GM issued a special coverage adjustment (N192268220) to cover repairs, which often involve replacing a microswitch in the shifter assembly or the shifter harness.)
• Brake Vacuum Pump Failure 🔴 High — Can occur on various models, leading to a hard brake pedal and loss of power brake assist. (Ref: Special coverage adjustment N202313440 was issued for some models for a potential leak, though outright failure is also reported.)
• Reduced Engine Power / Stalling 🟠 Medium — Often tied to issues with the electronic throttle body or accelerator pedal position sensor, particularly on 9th gen models. (Ref: TSBs have been issued for related codes like P2138.)
• Hesitation During Acceleration (1.5L Engine) 🟡 Low — Common on 2016-2017 models. A GM TSB points to a pin shifting out of place in the high-pressure fuel pump, causing the ECM to alter ignition timing. (Ref: Yes, a TSB addresses this specific fuel pump pin issue.)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific repair, using used parts is generally not recommended. The primary failure components (sensor, internal harness) are wear items located inside the transmission. The significant labor cost to access them makes installing a used part with unknown history a major financial risk.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the donor vehicle was not in a severe front-end collision that could have damaged the transmission case or connectors.
• If possible, check the color and smell of the transmission fluid from the donor vehicle. Dark, burnt-smelling fluid is a red flag for internal issues.
• Ask for the VIN to verify the donor vehicle's build date to ensure compatibility, especially regarding the pre/post March 2017 part change.

OEM-only on this vehicle (don't cheap out):

• Internal Transmission Wiring Harness Kit (ACDelco/GM Genuine #24292335)
• Transmission Control Module (TCM)

Aftermarket brands forum-validated for this vehicle:

• ACDelco (GM Genuine) for sensors and electronics is the safest choice.
• NTK/NGK is a reputable brand for sensors.
• Fel-Pro for gaskets.

Brands owners have reported issues with on this vehicle:

• Avoid unbranded, no-name electronic sensors from online marketplaces. The potential for premature failure is high, and the cost of re-doing the labor far outweighs any initial savings.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0700 — A general transmission control system malfunction code that is likely to be present whenever P0722 is stored.
• P0717 — An input speed sensor circuit code that often appears alongside P0722 during transmission sensor failures.
• P0721 — A related output speed sensor range/performance code mentioned as a companion to P0722 in diagnostic procedures.
• P2138 — A code related to the accelerator pedal position sensor which, like P0722, can cause reduced engine power or hesitation symptoms.

Frequently Asked Questions