Chrysler Repair: 90 check engine light on: how to get codes?, plymouth voyager, obd ii

Question
My maintance light is on and I would like to know which tool I need to buy to turn it off.I did replace both speed readers in my 1990 plymouth voyager 3.3 Transmission and now the Trans shift great thanks to your info.Now I just got get this light out.HELP I don't think its an OBD II it might be an RBD II ? I really don't know. Thanks for your time.rhino

Answer
Hi Ron,
The light means of course that something has been detected that would significantly increase pollution. Fortunately you don't have to buy a reader to get the fault code. You have an OBD-I system in your '90; the OBD-II didn't start until the '96 model year except for the Neon that began in '95. Becauss of that, just use the ignition key:"on-off-on-off-on and then leave it on", doing that in an elapsed time of 5 seconds or less. Then watch the check engine light which also remains "on" to begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat to verify that you have an accurate set of counts. Then group the counts in pairs as they read out to form the two-digit numbers which constitute the fault codes. The last two sets of flashes will be 5 in each, which means a number 55, and that is the code for "end of readout". You can either get a code translator at www.allpar.com/fix/codes.html or you can write me back and tell me numbers and I can then tell you specifically what to do to correct the fault and thus cancel the code. The present codes can be cancelled by merely disconnecting the - post of the battery for a minute or so. But if the fault is still present the code will be reset and turn on the check engine light. That is how you can verify whether or not the fault is repaired. Let me know what you learn. I am pleased that you were able to get the trans to work smoothly once more. It could have been something much more expensive, so count you blessings!
Roland