The Subaru Legacy has always been a dependable car, but even the best cars have problems. When the check engine light (CEL) comes on, it can be a cause for concern. The CEL indicates that something is wrong with your car, specifically the emissions system. The problem can be as simple as a loose gas cap, or it could be something more serious. Subaru Legacy CEL codes fall into two categories. OBD-I is the system used before 1996, and OBD-II is the CEL system that has been used since then.
Remove the bottom dash panel. The panel runs from the bottom of your steering wheel toward your gas and brake pedals. It should simply pop off.
Locate the two pairs of disconnected wires. One pair is narrow and black, and the other pair has wide green connectors.
Connect the black wires. Turn the ignition to "ON" but do not start the car.
Record your CEL flashes. There will be a combination of sustained flashes and quick flashes. The number of sustained flashes is the first digit of your CEL code, and the number of quick flashes is the second digit of your CEL code. For example, three sustained flashes followed by three quick flashes would be code number 33.
Check your deciphered CEL code with your year-specific service manual to find what the code means.
Remove the lower dashboard panel that's under the steering wheel on the driver's side.
Locate the diagnostic connection cable. The cable will not be connected to anything and the plug should resemble the one on your OBD-II scanner.
Plug your scanner into the diagnostic cable. Turn the ignition to "ON" but do not start your car.
Read the code displayed on the scanner. Cross-reference the code with your year-specific service manual to identify the problem.
