My speedometer goes wonky at times

Already replaced OOS and the input speed sensor problem is intermittent just had shop run tests they did circuit check from the sensors to pcm with no problems - also checked connectors and they are good.

What is your Vehicle info? Had same exact problem on 98 Jeep Grand Cherokee 4.0. BCM checks VIN on PCM and if differnt it will not start. Did all the same replacements/checks. After talking over with half a dozen of my mechanic buddies - pretty sure it my PCM. Becarefull about used and online stores/ebay. A lot of them get really bad reviews or are a complete ripoff with forged 5 star ratings. I used these people below and they seem great so far and one of the only few sites that didn't try to sell me something that they didn't tell me needed addition programing or flat just would not work (for mine you can us a 98 on 96 & 97 but not a 96-97 on a 98). ams auto module source Davies FL 4690 SW 83rd Terrace Davie, FL 33328 (954) 279-2040 www.automodulesource.com BTW - Could have got a Cardone at Rock Auto but they could not program it. According to you vehicle might want to check them out too - Hope this save some time and frustration!

Wonky - That's a Technical term - Right;) My Control Modulal P/N was also P56044513AC Good Luck - Keep ya Posted!