IDDA Garage

13	Open Oxygen Sensor Circuit
14	Coolant Sensor Circuit (Signal Voltage Low)
15	Coolant Sensor Circuit (Signal Voltage High)
21	Throttle Position Sensor (Signal Voltage High)
22	Throttle Position Sensor (Signal Voltage Low)
24	VSS Buffer Not Attach to I.P.Clstr. '85 VIN 3(3.8L)MPFI
32	EGR Vacuum Control
33	Mass Air Flow Sensor (Signal Frequency High)
34	Mass Air Flow Sensor (Signal Frequency Low)
42	Electronic Spark Timing, 1985 VIN 3 (3.8L) MPFI
42	HEI-W/EST
43	Electronic Spark Control (ESC) Circuit
44	Oxygen Sensor Circuit (Lean Exhaust Indicated)
45	Oxygen Sensor Circuit (Rich Exhaust Indicated)
51	PROM
52	CALPAK
55	ECM

To extract a trouble from the computer for diagnostic purposes, the Assembly Line Communication Link (ALDL) connector is used.

Ground terminals A and B with the ignition "ON" and engine not running. The system will enter the diagnostic mode. In this mode, the computer will display a 12, three consecutive times, by flashing the "CHECK ENGINE", "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR LAMP" or light. A 12 consists of one flash, a short pause, then two flashes in rapid succession.

After 12 is displayed, any stored trouble s will be displayed by flashing the "CHECK ENGINE", "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR LAMP" light. All s are displayed 3 times each then a 12 will repeat. In the diagnostic mode, the computer will also energize all computer controlled relays and solenoids.