Engine Running Quick Test

Start and allow engine idle to stabilize. Engine must reach normal operating temperature. Upper radiator hose should be hot and pressurized. Check that carburetor is off high cam.
Turn ignition off. Connect a jumper wire from Self-Test Input (STI) to Pin 2. See Fig 1 .

Fig 1: Meter Hook-Up for Reading Codes
Courtesy of FORD MOTOR CO.
Place volt-ohmmeter (VOM) on a DC voltage range of 0 to 15 volts. Connect VOM from battery positive post to Pin 4 Self-Test Output (STO) in the Self-Test Connector.
Start and allow engine idle to stabilize. Engine must reach normal operating temperature. Upper radiator hose should be hot and pressurized. Check that carburetor is off high cam.
Observe and record all service codes. Service codes are transmitted to the Self-Test Output terminal in the form of timed pulses. On the VOM each pulse equals one meter sweep.
- One-half second on-time pulse for each digit.
- Two seconds off-time between digits.
- Four seconds off-time between codes.
- Eight to twelve seconds before fast and service codes.

Example: 6 pulses (sweeps) equals digit 6; two second pause then 8 pulses (sweeps) equals digit 8, this will equal code 68.

SERVICE CODES

Output Code

Go To

Test 1, Step 1)

Test 4

⁽¹⁾ Adjust Minimum Speed Idle Screw

Test 2

Test 3

NO CODES

Test 5

⁽¹⁾	See appropriate article in the TUNE-UP section.

Fig 2: 2.0L ISC-E Wiring Diagram

Courtesy of FORD MOTOR CO.

NOTE: In the following diagnostic charts, circuits and illustrations are supplied by courtesy of Ford Motor Co.