If use of an OBD-II type scan tool is not available, DTCs can be retrieved by changing PCM output from Mode 1 to Mode 2. Mode 1 is the normal malfunction warning mode. Mode 2 displays self-diagnostic results.
To switch PCM output from Mode 1 to Mode 2, locate the self-test harness connector. See Fig 3. Turn ignition on. Disconnect self-test harness connector and jump terminals No. 3 and 6 together. Disconnect jumper wire after being connected for at least 2 seconds. Reconnect self-test connector. MIL should now be in Mode 2. When in Mode 2 with engine off, MIL should begin flashing codes.
The 4-digit DTCs (flash codes) are read as two 2-digit numbers. The first 2-digit number is indicated by a series of long flashes followed by a series of short flashes. E.g. one long flash followed by 2 short flashes indicates DTC 0102. See Fig 2. The DTCs retrieved by MIL are not numerically the same as DTCs retrieved from a scan tool.
Write down DTCs and repair in order of priority. See DTC PRIORITY IDENTIFICATION table. To determine which circuit test to use, see appropriate DTC IDENTIFICATION table under SUMMARY . After retrieving DTCs or performing a repair, clear DTCs from PCM memory. See CLEARING CODES . If no DTCs or DTC P0000/MIL 0505 (pass code) were retrieved and fault still exists, proceed to TESTS W/O CODES article for diagnosis by symptom.

Fig 1: Turning Test Mode Selector

Courtesy of FORD MOTOR CO.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Without Scan Tool (Quest)