Although it may be nothing serious, the engine should be attended to immediately if the check engine light comes on in any vehicle, including the Toyota RAV4. A crossover sport utility vehicle introduced in 1994, it features an intricate electrical system that warns the driver when something is amiss with the engine. Sometimes the problem may be as simple as needing to add oil to the engine. Other times, however, it may mean there's a more significant problem brewing.
Open the hood on your RAV4. Check the battery cables, to make sure they are tight. If they are not, tighten them with the socket set.
Turn the multimeter on, and select the voltage setting. Place the positive lead wire to the positive battery terminal, which will be either red or marked by a (+) sign, and place the negative meter lead to the negative battery cable. If the voltage is less than 12 volts, the battery may need to be replaced or, at least, charged.
Locate the oil dipstick, and remove it. It is located on the right-hand side of the engine block, on the driver's side. Wipe it with the rag, insert it back into the dipstick tube, withdraw it again and examine the level on the dipstick. If it is low, replace the dipstick, remove the oil fill cap and add a quart of oil. Check the level on the dipstick again, to see if an additional quart is needed. If it is, add it.
Inspect the belts to make sure they're all on and that none has broken or come off. If a belt has broken, have the vehicle serviced immediately by a technician.
Check the radiator cap to make sure it is cool. If not, allow it to cool off so the pressure subsides. When it's cool, push down on the radiator cap, and twist it to the left to remove it. Start the RAV4, and check the level. If it is low, add water and replace the cap. Also inspect the coolant overflow tank, which is connected to the radiator. If it is low, add a quart of coolant to the reservoir tank.
Start the RAV4, and remove the automatic transmission fluid dipstick located on the driver's side rear section of the engine compartment. If it is low, stop the vehicle and add a quart of transmission fluid.
