Warning light fault detection system

1996 Dodge Dekota, My vehicle failed the required biennial smog check because the car fault analysis computer would not communicate with the smog check computer. In all other respects my car passed the test. I need to know what prevented my car computer from responding. Any suggestions? NOTE" as I have limited income any do-it-yourself suggestion would be helpful. The local Dodge dealer is a crook so don’t go there.

My recommendation is to contact your state’s Department of Motor Vehicles and find out what the protocol is for this situation. They may have an alternatiive that you can present to the inspector.

Short of that you’d need to get a diagnosis.

Did you reset the computer recently? The ODB-II system requires a certain amount of data before it is ‘Emissions-Ready’. If it was reset, it may need some more ‘run-time’ before it will communicate properly.

Where they plug in the “smog check computer” is the DLC (Data Link Connector). It’s 12 volt power is on terminal #16 which comes from #2 fuse(which also, powers the dome light, radio, glove box, etc.). You can check #2 fuse. You can check terminal #16, on the DLC, for power, 12 volts, with a digital voltmeter (multimeter). The wiring diagrams show 4 wires going between the PCM (engine computer) and the DLC test connector. You could check the wiring to make sure it is whole. Disconnect the battery. Disconnect the C plug from the engine computer (PCM). Set the test meter to read OHMS. Put one test meter probe on the PCM plug terminal C27 and the other probe tip on the DLC terminal #7. C28 goes to DLC # 11. C29 goes to DLC # 6. C30 goes to DLC #3. To see the following wiring diagram, click on this: http://search.ebscohost.com. User ID = user. Password = password. Click Login. Scroll to the bottom of the page and click on: Auto Repair Reference Center. Next, select your truck’s year, make, model and engine. Click on: wiring diagrams. Click: Engine Controls. Click on: [5.2L]. Click: |drawing 3).

Click on this site for a drawing of the DLC connector and the terminal numbers: http://pinouts.ru/CarElectronics/car_obd2_pinout.shtml