2023 GMC Terrain Problems: 6 Known Issues

On the 2018-2025 GMC Terrain, the 2018+ Terrain with the 1.5L turbocharged engine (LFV/LYX) experiences PCV (Positive Crankcase Ventilation) diaphragm failure inside the valve cover. The integrated PCV diaphragm tears, causing excessive crankcase pressure that forces oil into the intake manifold and intercooler. Symptoms include oily residue around the air intake and intercooler outlet pipe. In severe cases, excessive crankcase pressure also causes coolant intrusion into the combustion chamber. GM issued TSB PIT5697 for this issue. This is the same problem affecting the Chevrolet Equinox 1.5T of the same era.

On the 2018-2024 GMC Terrain, on the second-generation Terrain (2018+) with the turbocharged 1.5L LYX or 2.0L LTG engine, the air-to-air charge air cooler (intercooler) accumulates condensate from humid or rainy driving plus PCV-borne moisture. In cold ambient temperatures that water freezes inside the CAC core, restricting charge airflow. GM documents this in service bulletin 18-NA-020, originally issued for 2018-2022 and later expanded through the 2024 model year. Owners on the Terrain/Equinox forum describe ice and standing water inside the charge tube. This is a distinct failure from the CAC outlet duct popping off the throttle body and from the 1.5L PCV coolant/oil intrusion problem - here the cooler itself is obstructed by ice or contamination, not disconnected.

On the 2023 GMC Terrain, gM recalled 2023 Terrain vehicles built with ventilated front passenger seats because the Occupant Classification System may fail to properly disable the front passenger airbag when a small child or a child restraint is detected in that seat. If the airbag deploys against a child or a rear-facing child seat it can cause serious or fatal injury. The defect is specific to the ventilated-seat option - Terrains without ventilated front passenger seats are not in the population, which is exactly the kind of trim-level distinction that gets lost when this is described generically as 'an airbag recall.'

On the 2020-2023 GMC Terrain, gM recalled 2020-2023 Terrain vehicles because excessive powder coating on the four rear-seat lower child seat LATCH anchorage bars can prevent a child restraint from being properly installed or securely latched. A child seat that will not seat fully on the anchor may not restrain the child in a crash. This is a manufacturing/finish defect on the anchor bars themselves rather than a structural failure, and it is invisible to most owners until they actually try to install a LATCH-attached seat and cannot get a positive click.

On the 2021-2023 GMC Terrain 1.5L Turbo I4 (LYX), on 1.5L turbo Terrains, a component inside the high-pressure fuel pump can fracture prematurely, generating metallic debris that migrates through the fuel line and blocks the injector inlets, starving the engine of fuel and causing sudden stalling and loss of power while driving - a crash risk. GM recall N222372310 (NHTSA 23V-013) covers the 2022 Terrain; broader inadequate-fuel-flow actions span the 2021-2023 range.

On the 2010-2024 GMC Terrain, terrain front and rear hub assemblies integrate the ABS magnetic encoder ring into the bearing's inboard seal, where it sits directly exposed to road salt and moisture. Two distinct failure modes result. The mechanical one is the familiar humming or roaring that rises with speed and changes when loading the bearing in a wide turn. The one that fools owners and shops is encoder-ring failure on a bearing that is still mechanically tight and silent: the wheel speed signal drops out and the vehicle sets a wheel speed sensor code with ABS, traction control and stability control disabled. Replacing only the external sensor does not fix it, because the encoder is part of the bearing. Both generations are affected, with salt-belt vehicles failing earliest.