1. Locate the OBD-II port. In the 1997 Ford Ranger, it's usually located under the dashboard, on the driver's side.
2. Connect an OBD-II scanner. Plug one end of the scanner into the OBD-II port and the other end into your diagnostic computer or scan tool.
3. Turn on the ignition. Do not start the engine yet.
4. Follow the prompts on the scanner. The scanner will display the engine light codes and their descriptions.
Option 2: Using the EEC-IV Self-Test Mode
1. Prepare your vehicle. Turn off the engine and make sure the transmission is in Park (for automatics) or Neutral (for manuals).
2. Connect a jumper wire. Locate the EEC-IV diagnostic connector, which is usually near the battery. Connect a jumper wire between the TE1 and GND terminals.
3. Turn on the ignition. Do not start the engine.
4. Count the flashes. The Check Engine light will flash a series of codes, with each code consisting of two digits. The first digit represents the tens place, and the second digit represents the ones place. For example, if you see two flashes followed by three flashes, the code is 23.
5. Write down the codes. Write down the codes as you see them, and then look up their descriptions in a Ford Ranger repair manual.
Option 3: Using a Code Reader
If you don't have an OBD-II scanner or the EEC-IV diagnostic tools, you can take your vehicle to an auto parts store or mechanic to have the engine light codes read.
