Get computer codes for a 1992 caprice classic?

Answer 1

Locate the diagnostic connector just under and more to the drivers side center of the dashbord, take a paper clip, or if you want to do it like the pro's, purchace a OBD-1 diagnostic reader, or just go to auto zone, they will read it for you for free, anyway, straighten it out, then bend it into a say 1/2 " U.

Place the "jumper" clip into the 2, A and B, diagnostic pin placement's, turn your key on, do not start it, and watch the check engine light, it will flash, if working correctly, a "12" code, which is the start of the ECU's trouble code memory, it will flash once, then twice, denoting a "12" code, letting you know the codes if any are about to run, you'll need a list of codes for your car to know what it is telling you, the trouble codes say, a 44, flashes 4 times twice, then again 4 times twice , as the 12 code will do, giving you time to collect them, if their is more than one.

13 Open Oxygen Sensor Circuit 14 Coolant Temperature Sensor (High Temp Indicated) 15 Coolant Temperature Sensor (Low Temp Indicated) 21 Throttle Position Sensor (Signal Voltage High) 22 Throttle Position Sensor (Signal Voltage Low) 23 Manifold Air Temperature (MAT) Low Temp Indicated 24 Vehicle Speed Sensor (VSS) Circuit 25Manifold Air Temperature (MAT) High Temp Indicated 32 Exhaust Gas Recirculation (EGR) Circuit 33 Manifold Absolute Pressure Sensor Circuit (High Sig.) 34 Manifold Absolute Pressure Sensor Circuit (Low Sig.) 42 Electronic Spark Timing (EST) Circuit 43 Electronic Spark Control (ESC) Circuit 44 Oxygen Sensor Circuit (Lean Exhaust Indicated) 45 Oxygen Sensor Circuit (Rich Exhaust Indicated) 51 Faulty PROM 54 Fuel Pump Circuit (Low Voltage)5555 ECM Error

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.

Here's a description of the diagnostic connector, and the proper pin placement to run the codes.

http://autorepair.about.com/library/ts/obd-i/bl-dtcs-94.htm?once=true&

ALDL Connector (Located Underdash)

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