Engine Control Module: Testing and Inspection

Fig. 14a Output signal diagnosis chart (Part 1 of 2). 1985-86 Colt & 1985 Conquest:

Fig. 14b Output signal diagnosis chart (Part 2 of 2). 1985-86 Colt & 1985 Conquest:

Fig. 17 ECU terminal identification. Exc. Conquest w/intercooler:

Fig. 18 ECU terminal identification. Conquest w/intercooler:

Using output signal diagnosis chart, Fig. 14 , connect voltmeter to diagnostic connector, Fig. 17 or Fig 18, as specified in ``Terminal Location of Computer'' column in diagnostic chart. Check voltage at each terminal, ensuring tests are made under conditions specified.
When checking the ISC motor position switch, if ignition switch is turned on for 15 seconds or more, the reading will drop momentarily below 5 volts. When checking pressure sensor with engine idling, the reading will increase momentarily to 1.5-2.6 volts every 2 minutes.