I HAVE A 2007 MERCURY MILAN
150K miles
GIVING AN ERROR CODE P0720
BEFORE RECENT REPAIRS, THE CAR WAS DOING CRAZY HARD SHIFTING AND JUMPING. I ALSO HAVE AN ISSUE WITH THE SPEEDOMETER AND RPM GAUGES ACTING CRAZY - WE REPLACED BOTH SENSORS, AND STILL GOT THE CODE, SO MY HUSBAND CHECKED ALL OF THE CONNECTIONS(NOTHING VISIBLY WRONG) AND EVENTUALLY TRIED REPLACING PART OF THE WIRING HARNESS. ALONG WITH THIS REPAIR, WE ALSO REPLACED ALL OF THE MOTOR MOUNTS WHICH WERE WORN OUT. HE ALSO CHECKED/CHANGED THE TRANSMISSION FLUID.
AFTER THESE REPAIRS, MY CAR DOES MINIMAL HARD SHIFTING, BUT WE STILL GET THE CODE. THERE IS STILL A DELAYED RESPONSE WITH THE SPEEDOMETER- IT USUALLY WON'T ACTIVATE UNTIL I GET TO ABOUT 35 MPH, THEN IT WILL GENTLY KICK AND THE WRENCH LIGHT WILL COME ON. I HAVE ALSO NOTICED THAT MY DOOR LOCKS WON'T ACTIVATE UNTIL THE SPEEDOMETER BEGINGS TO REGISTER- THERE IS A DEFINITE DELAY WITH THOSE LOCKS AS WELL.
WONDERING IF THESE HOLD THE ANSWER- THE DELAYED SPEEDOMETER/HARD SHIFT, DOOR LOCK ACTIVATION, ERROR CODE- SINCE THEY ALL HAPPEN AT THE SAME TIME....
ALSO, IF I TRY TO GET IT UP PAST 60 MPH- IT SEEMS LIKES ITS RUNNING HIGH RPMS 35k AND WON'T SWITCH TO THE HIGHEST GEAR. MY HUSBAND IS NOW CONSIDERING LOOKING AT A SHIFITNG CABLE THAT RUNS IN FRONT OF THE TRANSMISSION.
{black}:shocked: SOMEONE HAS SUGGESTED THAT WE PURCHASE THE ORIGINAL TRANSMISSION FLUID FROM THE FORD DEALER-I'M NOT SURE IF THAT IS NECESSARY- SINCE WE JUST CHANGED IT WITH O'REILLY'S BRAND PREMIUM ATF.
THERE ARE LOTS OF OTHER YOUTUBE VIDEOS WITH PEOPLE EXPERIENCING THIS SAME ERROR CODE ISSUE WITH LITTLE RESOLVE.
{black}:idontknow: I WOULD LOVE YOUR INSIGHT.
FORGOT TO MENTION THAT THIS TRANSMISSION IS APARENLTY MANUFACTURED BY MAZDA- SEVERAL OF THE PARTS WE PURCHASED ARE COMPATIBLE WITH SEVERAL MAZDA MODELS.
I think your problem is directly related to wire chaffing. Unfortunately it happens on these cars often. When this code pops up I typically tell my customer to kick em as it's not always easy to get lucky with just replacing the OSS. When replacing part of the wiring harness, was it near the PCM? If I remember correctly, it's located near the brake master cylinder. I would check the continuity there. That was a problem on one of my customers 04 model. If that isn't an issue, sorry I could not provide more help :/
