The loudest year in the whole run at 452 complaints, and the launch of a nine-speed automatic that owners replace, replace again, and are never given a recall for. Only two recalls, and neither one touches the failure that dominates the file.

The car is in park, the dash says Shift to Park, and the engine will not switch off. Owners describe wiggling the lever, restarting repeatedly, and walking away from an unlocked car. 'Shifter assembly, Shift to Park. The 2018 Chevrolet Traverse repeatedly shows a shift to park message when the vehicle is already in park, this causes the vehicle to not turn off.' 'My vehicle has had the issue of putting the car in park and it says it is not in park, have to wiggle the gear shift around for it to recognize that the car is fully in park.' 'I am getting a shift to park error code on dashboard. The shifter gear is in park but the vehicle will not turn off. I have called the dealer several times and they are told the probl[em].' GM published thirteen bulletins about this message, all of them scoped to 2018 and 2019 only, and the earliest is a Preliminary Information that states 'Engineering is still investigating the root cause. The PI will be updated to a bulletin once the final root is understood.' It later became a service bulletin with a repair procedure. Two mechanics on video diagnose it the same way and it is the reassuring part of this issue: the fault is in the shifter assembly and its park position sensor, not the transmission. One scans a car and finds 'no fault in the engine, no fault in the transmission,' then goes to the shifter: 'here is the sensor located. This is the sensor which will give the signal.' The other simply replaces the shifter assembly. It is a part swap, not a gearbox.

GM ran Customer Support Program 18186 on 2018 Buick Enclave, Chevrolet Impala and Chevrolet Traverse vehicles with the 3.6L V6, option codes LFX or LFY. A Customer Support Program, or CSP, is the industry's quiet extended-warranty coverage for a known defect. GM's own words: the cars 'may have a condition where the piston oil control ring may have been damaged during installation. If this happened, it could lead to excess oil consumption in the combustion chamber and result in an engine misfire, a check engine light, and low oil levels. If the vehicle continues to be driven with an insufficient oil level, the engine could be severely damaged and the vehicle could lose propulsion.' The procedure is to inspect cylinders 2, 4 and 6, and 'if, during inspection, the technician sees evidence of cylinder wall scoring, (gouges), or a broken oil control ring is found, dealers are to replace the engine.' A reliability channel reports the downstream symptom in owner language: 'excessive oil consumption in the 3.6 L V6 engine, causing oil to burn, requiring frequent topups and potentially leading to engine damage.' GM's summary does not state years or mileage limits, so whether a given car is still eligible is a VIN question for a dealer, not something to assume. Check the oil level yourself before you buy either way.

Only two safety campaigns reach this year, and neither addresses the transmission complaints above. Recall 20V-668 (GM number N202313440) is the closest: on 2018 to 2020 Traverses and a long list of GM siblings, 'the start/stop accumulator endcap may have missing bolts,' and missing bolts 'could result in a transmission oil leak and may progress to a loss of propulsion,' with fire risk if the fluid reaches an ignition source. Start-stop is the system that shuts the engine off at a red light and restarts it when you lift off the brake; the accumulator is the part that keeps transmission pressure up while the engine is off. Dealers inspect and replace it free. Recall 21V-246 (GM number N202321200) covers side curtain air bags that 'may not be properly attached,' remedied by realigning or replacing weld nuts. Its summary reads 2010 to 2019 Traverse, but resolved on NHTSA's campaign-number endpoint it covers 108 vehicles in total across every make and model year, so the odds it is your car are small. Separately, GM ran an emission recall on 2018 cars with the 2.0L turbo engine whose engine control module 'may not respond to test tools with the correct Calibration Verification Number,' which can fail an emissions inspection. That is an emission recall, handled outside the safety recall system, and it is why it does not appear in the count of two.

A weld holding the mounting bracket to the front exhaust pipe cracks, the bracket separates, and a hole opens in the pipe. The symptom is a rattle and then a roar, and in the worst reports fumes in the cabin. GM's Special Coverage language, which appears in bulletins scoped to 2018 through 2023: 'certain vehicles may have a condition that could cause the mounting bracket on the front exhaust pipe to separate from the pipe. If this condition occurs, a hole may develop in the exhaust pipe at the bracket location, and a rattling or increased exhaust noise may be heard. Dealers are to replace the front exhaust pipe as necessary. The repairs will be made at no charge to the customer.' The version filed for 2023 cars is the only one that states terms, and they are generous: fifteen years or 150,000 miles from the in-service date, regardless of ownership, with reimbursement for owners who already paid. On 2018 the picture is murkier. One owner in this file writes: 'Exhaust weld broken (several times) same as special coverage adjustment n212356540 front exhaust pipe. This is a well known problem but gm refuses to fix 2018s.' That GM internal number is owner-reported, not read from a GM document, so treat it as a pointer for the dealer rather than a guarantee. Ask a dealer to check the VIN against the Special Coverage before you accept a quote. If it is not covered, the repair is small: an owner-mechanic on a later Traverse was quoted $380 to have a dealer fit the pipe or $175 to buy the part and do it himself.

Three smaller documented items on this year. First, GM published a bulletin for an 'Intermittent Service Power Brake Assist Message With a Brake Shudder and Possible DTC P0557 Set/Stored,' caused by the power brake booster vacuum sensor giving intermittent readings; the fix is a new vacuum check valve and hose. A DTC is a Diagnostic Trouble Code, the number a scan tool reads out of the car's computer. Second, a combined driveability bulletin names 'Transmission Shudder, Low Idle, Stalling after Auto Start, Reduced Engine Power Displayed on Driver Information Center, Malfunction Indicator Lamp Illuminated' together with a list of engine and transmission codes. If a 2018 stalls when the start-stop system tries to restart it, that is a documented condition rather than a mystery. Third, a Customer Support Program covers 2018 to 2020 cars with second-row bench seats where the middle seat belt buckle 'can fall down between the second row bench seats and be damaged when one portion of the bench is moved relative to the o[ther].' Dealers add an elastic strap and replace the buckle if damaged. Bench-seat cars only, so if yours has captain's chairs it does not apply.