2026 Mercedes-Benz AMG GLS63

My vehicle has violently jolted 10+ times while driving at low speeds (15–30 mph) in all drive modes. The jolting is severe enough to feel like being rear-ended and poses an immediate safety hazard. The check engine light came on during one incident. My dealership told me they cannot diagnose or repair the vehicle because they do not yet have software for 2026 Mercedes models, leaving the vehicle unrepairable and unsafe to operate. I no longer feel safe driving this vehicle and am requesting investigation and manufacturer action.

NHTSA ID

11703355

Incident

Dec 3, 2025

Complaint Customers may notice a check engine light in the instrument cluster and may also complain of rough running. One or more of the following DTCs may be stored in the ME control unit (N3/10): P227900 ‑ A leak was detected in the intake air system P152B00 ‑ A leak was detected in the intake air system (cylinder bank 1) P152C00 ‑ A leak was detected in the intake air system (cylinder bank 2) Cause Root cause varies Remedy Check the intake and the evaporative emissions system for leak tightness. Should you identify any leaks, repair them, clear the DTC(s) and test drive the vehicle. If the codes do not return, release the vehicle back to the customer. If the codes do return, then perform the tests located in the attached PDF titled "air leak work instructions". Then, open a TIPS case with the following information: • Initial quick test • ME control unit log • Detailed results (including XENTRY print outs) of the tests performed in the "air leak work instructions"

Issue On certain subject vehicles, the transmission control unit (VGS) does not conform to current production specifications. It is possible that the polarities of the magnets in the transmission control unit (VGS) could have been incorrectly installed, leading to potential shift quality issues and gear lockouts. Remedy MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the software of the transmission control unit in the affected vehicles.

Complaint Harsh upshifts, downshifts, or jolting in lower gears when accelerating. Cause Incorrectly installed (rotated) rotational speed sensors on the EHS (VGS Control Unit) can cause abnormalities in signals. As a result, poor adaptation values are stored and harsh gearshifts are felt. This only affects vehicles with VGS control units produced between days 185‑296 of 2025 (July 4, 2025‑ October 23, 2025). It is possible to check the production date of the VGS through the EEPROM .txt file (Figure 1) or on the VGS hardware (Figure 2). Remedy If the production date is or is within 25185‑25296 (07/4/25‑10/23/25): IPR will recognize these cases and advise updating of VGS software. Please ensure your XENTRY has all the latest Addons installed before proceeding. 1. Perform IPR and follow recommended steps • update VGS software • perform standstill adaptation Hardware replacement is no longer necessary for this root cause! 2. Perform 5‑7x driving adaptations of 3‑4 upshift and 5‑4 downshift • use the attached guide and steps below, (also found in Startek NG > Passenger > Drivetrain) for the 5‑4 downshift: ‑ Start the coast or braking from a higher engine speed (if the vehicle shifts into 6th, restart the acceleration up to 5th gear) • 5‑7 downshifts in Comfort while coasting • 5‑7 downshifts in Sport while coasting • 5‑7 downshifts in Comfort with consistent light to medium braking • 5‑7 downshifts in Sport with consistent light to medium braking If the production date is outside of this range: This LI is not applicable. 1. Perform IPR and follow recommended instruction

Complaint Customer concern of Air Conditioning not cooling. *NOTE ‑ Use of tracer DYE for leak checks is not approved. Only approved leak check procedures as per WIS are approved. Cause Possible refrigerant leak. Remedy Perform the following measures : *Important* ‑ Photo documentation requirement is no longer in effect as of 10/1/2025. Remedy 1: Replace Evaporator (Only applies to vehicles produced PRIOR to April 15, 2022 and has NOT had the evaporator replaced previously) 1. Ensure that the rest of the AC system has been thoroughly checked for leaks with forming gas as per WIS before condemning the evaporator. 2. If no other leaks are found, replace the evaporator 3. *Important* ‑ when you get the new evaporator, check the expansion valve bracket to see if there are any bends (see attachment "Bent Bracket"). a. If bent, remove the expansion valve and bracket and check for damage to the flange (see attachment "Flange Damage"). i. If damage is found, order another evaporator and claim the part under parts warranty. The warranty claim MUST include a photo of the damage found. ii. If no damage is found, flip the bracket and torque to 7Nm. Check the evaporator for proper sealing before fully installing. b. If no bends are found, the evaporator should be installed in the vehicle. Note ‑ *If the evaporator housing has been opened or the evaporator or housing has been tampered with, the claim will be debited. Remedy 2: (Applies to all vehicles produced on or AFTER April 15, 2022 up to August 1, 2025) 1. Ensure that the entire AC system has been thoroughly checked for leaks with forming gas as per WIS . 2. If no leaks were found AND the system came in with no cooling/low charge, OR the evaporator is suspected of leaking: 3. Replace ONLY the expansion valve bracket, seals, and bolts as supplied in kit A 167 832 47 00, in accordance with the procedure outlined in WIS document AR83.30‑P‑5520ME. 4. IF THE PRODUCTION DATE IS BETWEEN JUNE 1, 2023 AND JULY 1, 2024, REPLACE THE DRYER AS WELL. (NOT THE CONDENSER) 5. After, charge the system and perform a few drive cycles. 6. Recheck the vehicle for leaks. 7. If no leaks are found, the vehicle can be released. 8. If a minor leak is detected that is less than 50ppm, then perform the following steps: • If a leak is detected, fill the system with forming gas • Close all doors and windows for 10 minutes. • Vehicle off with no blower activation. • Open the driver's door and measure ppm detection as soon as the door is open and the sniffer goes into the vehicle. • If no leaks are measured, fill the system and release. • If you still feel the evaporator is needed/leaks are still detected, a TIPS case is required for replacement. Provide all documentation listed in Remedy 3. Remedy 3: (Only applies to vehicles produced AFTER August 1, 2025) Ensure that the entire AC system has been thoroughly checked for leaks with forming gas as per WIS . If no leaks are found or the expansion valve has been found to be leaking, remove the expansion valve and check the bracket. If the bracket is bent, replace the expansion valve bracket, seals, and bolts as supplied in kit A 167 832 47 00. In the warranty submission, include photos of both sides of the bracket and a side profile so it can be seen that the bracket is bent. If the bracket is NOT bent or leaks from other locations are found, then open a TIPS case with the following: 1. Initial Quick Test 2. Create a short video of the actual pressures via AC machine, showing the engine running, and hold a copy of the VIN/RO in view as well. 3. OBS recording of XENTRY AC actual values of compressor request to be on and current value. (Instructions in Attachments) 4. Video recording of the leak being found via sniffer at the R/F AC drain after removing the under dash panel if the evaporator is suspected. (see attached videos) 5. If the evaporator is found to be leaking via sniffer, another video needs to be uploaded (or a continuation if only making the video after checks

Complaint Customer states that the yellow "Coolant" message is populated in the instrument cluster. The following DTC is found stored in the PTCU: P2B2A7A ‑ The speed of the 'Coolant pump' component part is too high. A leak or defective seal was detected Notes on fault code: The fault code concerns the right rear 15 W pump on the side of the transmission (M43/6, Figure 1, position C). The fault code concerning the speed that is too high is set because of air in the system (emergency dry run function) IMPORTANT: For model year 2024 and newer vehicles pump PN's A0005009100 and A0005008900 are the correct pumps Cause Air in the low‑temperature coolant circuit Remedy PLEASE READ ALL THE BELOW STEPS AND FOLLOW THEM IN ORDER. Step 1: With the engine cold, use XENTRY Diagnosis to activate the two pumps at the passenger front. As they are running, remove the cap from the low temp cooling circuit reservoir and observe the coolant. • If it overflows the reservoir, or blows out upon removal of the cap there is a restriction somewhere in the coolant lines. • This can take the form of a physical restriction inside of one of the lines or pumps or a damaged or kinked hardline or rubber hose. • Activate each pump in succession and listen to it using a stethoscope or by placing an ear to a screwdriver or other implement placed on the pump • Compare the sound and feel of each pump. An improperly functioning, bled, or faulty pump will make a very distinct churning noise. The pumps should be near silent and should not vibrate or heat up. • If you find a pump that is making more noise than the others it is most likely pulling in air from somewhere or is encountering a restriction (refer to the first point in this section) • If nothing of note is found, proceed to step 2. Step 2: Disassemble underfloor paneling and wheel well interior trim at front right to gain access to the two low temperature pumps. Take note of or photograph the part number of the pump holder, along with the production date. Step 3: For model year 2020‑2023 only, check the installation position of the pumps at the front right of the lowtemperature circuit (Fig. 1). Below are the correct specified part numbers at each location for these model years: • Outer: A 000 500 5500 (Fig. 1, position A) • Inner: A 000 500 3800 (Fig. 1; position B) • If installation position is NOK, continue to step 4 • If installation position is OK, skip to step 7 Step 4: Photograph the pump part numbers at the front right so that the QR‑code/DMC code and the part number are visible and legible save the pictures and label them appropriately if a TIPS case is required in the future. Step 5: For model year 2020‑2023 only, replace the affected pump(s) if the installed part number differs from the specified part number (see specified part number in step 3). Step 6: Use a vacuum bleeder to fill the cooling system of the low‑temperature circuit. Step 7: Vent the cooling system of the low‑temperature circuit using XENTRY. • NOTE: The cooling system of the low‑temperature circuit is vented in various stages. To start with, the pumps at front right are actuated at approx. 30%, then 50% and finally at 100%. At 100% actuation, the valve of the coolant circulating the pump at the side of the transmission is opened (Fig. 1; position C). Please ALWAYS observe the following points during the venting procedure: • The front right pumps always run simultaneously. These pumps must NEVER be operated separately of each other for actuation or for test purposes. • The pump at the rear of the transmission must run permanently after being actuated. If the pump only briefly starts‑up and then stops again, it is in a so‑called emergency dry run mode because there is too much air in the system. Please repeat the venting routine. If the rear pump at the side of the transmission remains in the emergency dry run mode, create a TIPS case, add the previously discovered findings to it and send it to the technical support team.

Subject vehicles were visible and flagged in VMI as “OPEN” under campaign 2026080002 in Netstar-VMI on September 25, 2026. Unrepaired affected vehicles were no longer shown as “OPEN” in VMI as of October 13, 2026. Instructions for remaining unrepaired vehicles will be published in a future campaign. Please note that all customer inquiries should be directed to the Customer Care Center at 1-800-FOR MERCEDES (1-800-367-6372).