2000-2020 Chevrolet Impala Problems: 16 Known Issues

The Passlock anti-theft system causes intermittent no-start conditions where the security light comes on and the engine is disabled. The ignition lock cylinder carries a magnet read by a Hall-effect sensor in the lock housing; when the sensor, its wiring, or the BCM connector terminals fail, the BCM detects a mismatch and fuel is locked out. The problem typically worsens progressively from occasional to daily. 225+ complaints were filed for the 2002 model year alone.

The 2000-2005 Impala was included in GM's 2014 ignition key recall 14V-400, which covered 5,877,718 vehicles across several GM models. The weight on the key ring and/or road conditions or some other jarring event can cause the ignition switch to move from the "Run" position to the "Accessory" or "Off" position while driving. When this happens, the engine shuts off, the power steering and brake boost are lost, and the airbags may not deploy — all without warning. The issue is exacerbated by heavy key chains that add weight and leverage on the ignition cylinder.

Impalas frequently throw a cluster of warnings at once — 'Engine Power Reduced,' 'Service StabiliTrak,' and 'Service Traction Control' — that are usually one underlying drive-by-wire fault rather than three separate failures. The most common root cause is the electronic throttle body actuator (or the dual throttle-position sensors inside it) going out of range; the accelerator pedal position sensors can also disagree. Because the ECM cross-checks these dual sensors, any disagreement forces the car into limp-home mode with drastically reduced power. Carbon buildup on the throttle plate aggravates it, especially in cold weather.

The Impala has the widest year span of any vehicle in GM recall 14V355000 - 2006 through 2014. The problem is not the key turning itself off on its own; it is the load hanging from it. NHTSA's record states that the weight on the key ring, combined with road conditions or some other jarring event, may cause the ignition switch to move out of the run position. Two things follow from that. First, the air bag system: with the key out of run the air bags may not deploy in a crash. Second, the driver loses engine power and, with it, power steering and power braking. GM's interim instruction to Impala owners was to drive with only the ignition key on the ring and the fob removed.

These Impala gauge clusters use small stepper motors to drive each needle, and GM's era-wide stepper-motor defect makes them fail prematurely. Typically one gauge sticks or reads wildly wrong first (speedometer stuck at 60 while parked, fuel pegged on full, temperature slammed to the red on a cold engine, or a stuck tachometer), then others follow over time. It starts intermittent and progressively worsens, and can be a safety concern when the speedometer is inaccurate.

The power window regulators in the 2006-2020 Impala fail frequently, causing windows to fall into the door, move slowly, or stop working entirely. The cable-style regulator uses thin steel cables that fray and break, or the motor gears strip. The driver window is the most commonly affected due to highest usage. In cold weather, ice can bind the window in the channel and burn out the motor when the switch is pressed. Some owners report windows falling into the door with a loud clunk.

General Motors recalled 2004 Chevrolet Impalas manufactured April 8, 2003 through June 23, 2003 because the valve cover gasket may leak. Leaking engine oil can reach the hot surface of the exhaust manifold, and GM's stated consequence is an increased risk of fire — which is why this is a safety recall rather than a routine gasket service. GM filed the defect report with NHTSA on April 2, 2015. The Impala is one of several GM cars swept into campaign 14574; the 330,742 units listed by NHTSA is the size of the whole campaign, covering every model in it, and should not be read as an Impala-specific number. As with any build-date recall, an Impala titled as a 2004 but assembled outside that spring 2003 window is not included.

GM recall 09V116000 covers 2000-2003 Chevrolet Impalas built with the 3.8L naturally aspirated V6. The problem is not the oil leak itself but where the oil ends up: under hard braking, drops of engine oil can be deposited on the exhaust manifold. If the manifold is hot enough and the oil makes its way below the heat shield, it can ignite into a small flame that may spread to the plastic spark plug wire channel and beyond, increasing the risk of an engine compartment fire. Impalas of these years fitted with other engines are outside the campaign, so confirm the engine before assuming your car is affected. The recall population NHTSA reports — 1,497,516 vehicles — is the campaign-wide total covering every GM model in the recall.

NHTSA lists the 2000 Impala in this recall when it left the factory with the 3800 V6 (L36) and one of the suspect Delphi fuel pressure regulators. Those regulators leak far more often than they should. On the Impala the leaked fuel does not simply drip away — it is drawn into the intake manifold through a vacuum line. Should the engine be cranked and fail to start, the fuel sitting in the manifold can be lit by a mistimed spark and backfire. NHTSA's stated consequence is a ruptured intake manifold, which can in turn displace a fuel line and pull an injector out of its bore, leaking fuel with a possibility of fire. Owner notification went out in phased mailings beginning June 30, 2004, with a second phase on September 30, 2004. Across every model in the campaign, 910,873 vehicles were involved.

The in-tank fuel level sensor (part of the sending unit on the fuel pump module) is a common failure on the Impala. The sensor's small metal contact 'teeth' wear against the resistor card as the float arm moves, and the arm itself can stick or bind. The result is a gauge that reads inaccurately or swings erratically between full and empty, often unrelated to actual fuel level. This can leave owners stranded by a gauge that shows fuel remaining when the tank is near empty.

The 4T65-E automatic transmission used in the 2000-2011 Impala is one of the most failure-prone GM transmissions. Common failures include the 1-2 accumulator piston cracking (causing harsh 1-2 shift), pressure control solenoid failure (erratic shifts and slipping), and the forward clutch hub cracking (complete loss of forward gears). The 3.8L supercharged models are especially hard on the 4T65-E due to higher torque output. Many 4T65-E transmissions fail between 80,000-120,000 miles.

The 2006-2013 Impala is notorious for internal breaks in the front ABS wheel-speed-sensor wiring harness. The factory routes and clamps the harness such that steering movement repeatedly flexes the wire; the copper conductors fracture inside the insulation while the outer jacket looks perfectly intact, making it hard to spot. The result is intermittent ABS, traction control, and StabiliTrak warnings — often appearing or clearing when the wheel is turned. Left front (C0035) is the most common, but both sides fail.

GM bulletin 07-06-02-006E describes coolant crossover gasket leakage on specified 2006-2010 Impala 3.5L/3.9L applications. Crossover designs differ and require matching gaskets. Water-pump leakage is a separate possible cause of coolant loss; residue location alone does not distinguish them.

The 2014-2020 Impala uses a belt-driven electric power steering system (RPO NJ2) on the steering rack. The motor can fail, causing loss of power steering assist (steering becomes very heavy). The steering control module can also lose communication, triggering warnings. GM recalled certain 2014 Impalas (NHTSA 14V-450) because a poor ground connection to the power steering control module could cut assist.

A repetitive clicking or knocking sound from behind the dash — often constant, sometimes only when the car is running or turned off — is a classic Impala blend door actuator failure. The plastic gears inside the small actuator motor strip out, so the actuator can no longer position the blend door. On dual-zone systems there are separate left and right actuators; a stuck door means one side blows hot while the other blows cold, or the temperature won't respond to the setting.

The intermediate steering shaft on the 2006-2020 Impala develops a clunk or pop felt through the steering wheel when turning, especially at low speeds and when going over bumps. The intermediate shaft connects the steering column to the steering gear and uses a slip joint that loses its lubrication over time, causing a binding and releasing action that creates the clunk. The noise is most noticeable when turning while going over speed bumps or entering driveways. GM issued TSB 01-02-32-001 for this issue.