2003 Jeep Grand Cherokee Problems
RepairPal has identified the most common problems with the 2003 Jeep Grand Cherokee based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
Due to warped front brake rotors or variations in the thickness of the rotors, brake pulsations may develop. The best method to reduce pulsations is to use an "On the Car" brake lathe (as long as the rotors are suitable for turning). "On the Car" equipment can correct variations (or "runout") in the rotor surfaces because it also corrects variations in other components (e.g. the hub).
Electrical contacts in the tail lamp housing tend to break or melt, which can cause the brake lights to fail or work intermittently. Complete inspection of the tail light housing and bulbs is recommended before replacing any parts.
Failure in the blower motor power module (automatic temperature controls) or resistor block (manual AC) may cause the heater blower motor to work only on the high setting. The connector to the power module/resistor block is known to overheat (and sometimes melt). The connector or terminals should be replaced; a replacement connector is available.
Temperature blend and recirculation doors commonly fail, which can cause the AC modes not to change or the temperature to be different on the left and right sides. If replacing blend air doors, a recirculation door, a door link, or a sub-assembly housing, new heating, ventilation and AC (HVAC) sub-assemblies are available that improve reliability.
A Check Engine Light may illuminate indicating a "Cylinder #3 Misfire." This normally occurs in hot weather after the vehicle has been driven, parked for ten to twenty minutes, and then restarted. Heat from the exhaust vaporizes fuel inside the #3 fuel injector and causes the misfire. Installing an insulator sleeve normally lowers the temperature enough so the fuel will not vaporize.
4.0L 6 Cylinder
Due to misfires, you may experience a loss of power when accelerating between 50 and 70 MPH (most noticeable below 32° F). This is commonly caused by carbon buildup on the valve stems, as a result the exhaust valves may close too late. All of the exhaust valves should be inspected and if necessary the engine should be decarbonized.
Leaks at the front and/or rear differential pinion seal and from the transfer case are common. Leakage from the transfer case normally occurs at the case-mating surfaces and require removal of the transfer case to reseal.
A ticking noise may be noted when vehicle is cold due to an exhaust leak caused by broken exhaust manifold bolts. Replacement of these bolts and associated gaskets is necessary to fix the condition.
The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops. There is also a revised vacuum check valve available to address this concern.
During light to moderate braking, if you experience a vibration in the steering wheel, floor, or seat, or a minor pulsation in the brake pedal, installing revised front brake calipers may help. If the brake calipers are silver in color, they are up-to-date. If the calipers are black in color, the revised calipers are needed and should be installed along with new front brake rotors.
Loose or worn suspension and steering components can cause a wobble or shaking in the steering wheel. It may happen at a certain speed and subside as the vehicle accelerates through the range. Tire balance can contribute to this as well.
The remote keyless entry system may not function intermittently. Our technicians tell us revised software for the wireless ignition node is available which can correct this concern.
Jeep issued an emissions recall in late 2006 to update the powertrain control module (PCM) software on certain 1996 vehicles. As part of the recall, the catalytic converter will also be inspected for damage and replaced as necessary. To see if your vehicle is included in the recall you can visit the Jeep website (owners' section) that allows owners to input their VIN number and check the recalls on their vehicle.