Chevrolet Blazer Problems & Known Issues

On 1995-2003 Blazer/S10 trucks, rust and debris build up on the front wheel speed sensor mounting surfaces, increasing the air gap between the sensor and the hub reluctor ring. The weakened signal makes the Kelsey-Hayes ABS falsely interpret a wheel as locking during light braking below about 5-10 mph, so the ABS buzzes, the pedal pushes back, and the truck lunges forward with extended stopping distance — without setting any trouble codes or lighting the ABS lamp. GM documented the condition in TSB 02-05-25-006B, and the identical corrosion mechanism triggered NHTSA recall 05V379000 covering about 1.35 million 1999-2002 GM full-size trucks and SUVs in salt-belt states.

The S-series Blazer's Kelsey-Hayes ABS system is prone to age-related faults: front wheel-speed sensors (integrated into the hub bearings) corrode and give erratic signals, the EBCM ground at the radiator support gets rusty/loose, and later Kelsey-Hayes 325 modules can fail internally. Symptoms include an ABS warning light, erratic wheel-speed codes, and in some cases the ABS pump running with the key off. Corroded grounds and connectors are a very common root cause on rust-belt trucks.

A 2024-model-year safety recall covers the gas Chevrolet Blazer alongside the Blazer EV, Equinox, and GMC Terrain. On the affected vehicles the door strikers can fracture. The striker is the anchor the door latch closes around, so once it breaks the door is no longer positively held shut and can open unexpectedly — including with the Blazer under way. NHTSA files the campaign under Structure: Body: Door and rates the consequence as an increased risk of injury or a crash. GM identifies it as campaign N232429911. It is a narrow recall: 265 vehicles in total across all four models in the campaign combined. Chevrolet mailed owner letters on January 24, 2024, so 2024 Blazer owners who bought used may never have seen the notice.

The heavy doors on two-door S-10 Blazers ride on small hinge pins with soft brass bushings that wear out — accelerated by lack of lubrication — letting the bushing holes in the hinge plates wallow out egg-shaped. The door then drops when opened, no longer aligns with the striker, and must be lifted or slammed to close. It is so universal on these trucks that multiple aftermarket oversized pin-and-bushing kits exist specifically for the platform.

The Vortec 4.3L V6 (like its 5.0L/5.7L siblings) used plastic-carrier lower intake manifold gaskets that erode and crack at the coolant ports from repeated thermal expansion cycles between the aluminum manifold and iron heads. Failures cluster between roughly 80,000 and 150,000 miles, leaking coolant externally at the front or rear of the manifold or internally into the lifter valley, where it contaminates the oil. Left unrepaired, an internal leak destroys bearings and can take out the engine.

The 4.3L Vortec V6 used a Central Port Injection system (CPI 1992-1995, CSFI 1996-2002) with a central injector body and six plastic poppet lines — the "spider" — mounted inside the intake manifold. The plastic lines and nut-kit connections crack and leak raw fuel into the plenum, while deposit buildup sticks the poppet valves open or closed, mis-fueling individual cylinders. The result is hard hot starts, persistent misfires, fuel-pressure leak-down, and a rich/fuel-smell condition; GM addressed sticking poppets in TSB 00-06-04-003B by back-servicing the CSFI unit with a redesigned MFI assembly.

The factory front lower ball joints on the S-series Blazer were sealed with no grease fittings and cannot be lubricated, leading to premature wear. NHTSA complaints document serious failures where the ball joint separates, the wheel folds under the vehicle, and steering control is lost - sometimes at low speed. 4WD models carry more front-end weight and are especially prone. This is a safety-critical wear item on high-mileage examples.

Push-button 4WD Blazers use an electric encoder motor on the NP1 electronic-shift transfer case, commanded by the Transfer Case Control Module (TCCM). The encoder motor's internal position sensor and gears wear out, and TCCM faults are equally common, so the transfer case fails to shift into or out of 4WD or gets stuck in a mode. Owners see flashing shift buttons or a Service 4WD light, and the system stores encoder fault codes readable via the TCCM's flash sequence.

4WD Blazers with the electric push-button New Process 233 transfer case (RPO NP8) use a TCCM-controlled encoder motor to shift ranges. The encoder motor, its position sensor, corroded selector-button contacts, and connector moisture are all common failure points, producing a "Service 4WD" warning, refusal to engage 4-Hi/4-Lo, or the case getting stuck in neutral. A frequent aggravating factor is corrosion at the button module and connectors.

S-series 4x4s use a front axle disconnect operated by a vacuum-diaphragm actuator (or the notoriously slow thermal linear actuator on early-90s trucks) to couple the front axle after the transfer case shifts. The actuator diaphragm cracks and the small vacuum lines and switch atop the transfer case leak, so the transfer case engages but the front wheels never pull — engagement is also progressively slower in cold weather as the thermal actuator ages. This is one of the most common 4WD complaints on these trucks, documented across years of forum threads and an entire aftermarket fix category.

The AGM battery required for the auto start-stop system degrades prematurely, often failing within 2-3 years. When the battery weakens, the start-stop system disables itself and various electrical warnings appear. The stop/start DC/DC converter (T19 power supply transformer) on 2019-2021 models can also fault (DTC P3055), disabling start-stop and turning on the check engine light.

The GM truck/SUV instrument clusters of this era use small air-core stepper motors to drive each gauge needle. Over time the internal dampening grease dries and the motors fail, causing needles to stick, read wildly wrong, or drop to zero. The speedometer and tachometer ("S" type motors on 1995-1999 clusters) are the most commonly affected, though the fuel gauge is also frequently impacted. It is a wear/age failure, not a sending-unit fault, so replacing senders does not fix it.

The 2019+ Blazer infotainment system (Chevrolet Infotainment 3) suffers from screen lockups, lag, and unresponsive touch input. The screen can freeze on the backup camera view or refuse button and touch input. GM bulletin 18-NA-376 attributes the rear-camera image freezing to software anomalies and released radio software update V509. Bluetooth and Apple CarPlay disconnections are also common. Some owners have had the radio module replaced.

The 2019+ Blazer with the 3.6L V6 (LGX) and 9-speed automatic transmission (9T65, RPO M3V) develops a torque converter clutch (TCC) shudder at low speeds (40 mph and below), typically when the TCC re-applies after a shift. GM bulletin PIP5608J addresses TCC shudder/surge issues; it has since been replaced by service bulletin 23-NA-072. The root cause involves excess lubrication on internal parts contaminating the transmission fluid. Some owners require torque converter or full transmission replacement.