Same shudder, same free fluid fix — and one owner who paid $500 for it anyway, then got quoted $8,000.

Distinct from the shudder and easy to confuse with it. GM documented that on a small number of 2018 and 2019 trucks the electrical connector to the transmission valve body solenoids may not be fully seated, setting code P2718 or P2720, lighting the check-engine lamp and dropping the transmission into limp-home mode with only limited forward gears. Dealers reseat the connectors free. A 2018 owner in the file reports a related code — P2738, pressure control solenoid valve 6, low voltage — with the transmission going into limp mode intermittently. If a truck has ever been described as "stuck in third gear" or "limp mode", this is the first thing to check by VIN, because it is free.

A 2018-specific free repair and the most safety-relevant item on this year's list. GM found contamination introduced into the brake pressure modulator valve — the hydraulic unit that controls ABS and stability-control braking — and says the result is spongy braking, an increase in stopping distance, and pulling to one side when you brake. The remedy is a new valve, at no charge, on 2018 Colorado and Canyon trucks. This is not a recall, so it does not show up where most buyers look. Brake firmly from 40 mph on a quiet road, feel for a soft pedal or a pull, and check it by VIN regardless of how it feels.

The only federal safety recall on the year. The high-pressure fuel pump can separate from its mounting flange and damage the high-pressure fuel line, which NHTSA says can create a fuel leak and increase the risk of a fire. The pump and the pipe are replaced free. 2018 is the last Colorado model year in the campaign. Confirm it shows completed by VIN.

One for diesel buyers specifically. A complaint on this year's file raises a materials defect in the rear crankshaft reluctor ring — the toothed ring the crankshaft position sensor reads — on the 2.8L LWN Duramax, noting the same engine is used in the Army's Infantry Squad Vehicle, which is based on the Colorado. It is a single filing rather than a cluster, and there is no GM programme covering it, so treat it as a thing to know rather than a thing to expect. What the federal record does show for the diesel in these years is a long run of aftertreatment work — bulletins on diesel exhaust fluid contamination, pump priming, particulate filter regeneration and NOx sensor readings — plus a voluntary emissions recall (not a safety recall) reprogramming the engine computer because it may not adequately warn the driver when the particulate filter is regenerating too often. The 2.8L's service burden is the emissions plumbing, not the bottom end.

GM documented that on certain 2017 to 2019 trucks, some kinds of off-road use can, in rare cases, set off the roof-rail airbags and seat-belt pretensioners. The free fix is a software reprogramme of the sensing and diagnostic module — the crash-sensing computer. If you are looking at a Z71 or a truck that has obviously been used off pavement, check this by VIN and confirm the airbags have never actually gone off.

Two liveability items that recur across this generation. The ignition switch can lock when you switch off, refusing to release the key and leaving the truck in accessory mode; the usual repair is a shifter assembly and owners note it is not covered by the powertrain warranty. And the touchscreen can go unresponsive or act on its own — one owner describes it randomly tapping apps, putting calls on hold, flipping pages and even switching the reversing camera on while driving. Cycle the key several times and spend five minutes on the screen before you commit.

Both apply to this year and both are VIN-gated and free. A front differential housing made with a 12 mm hole in its top surface gets the front axle rebuilt with the correct housing; the programme's scope runs 2015 through 2022. And a missing rear axle shaft c-clip causes rear brake squeal, brake pulsation and accelerated pad and rotor wear — worth knowing before you assume a squealing rear end just needs pads. A separate 2018 complaint describes a loud clunk from the differential on throttle take-up.