nico133

i have a 98 jeep cherokee sport and i cant erase the codes i get in the ecm i tryed with the scan tool and all i get is error, then i tryed reseting the ecm by unpluging the + terminal on the battery and grounding it for 30 sec and nothing...the light still comes on...i did manage to erase it, just holding the erase button on my scan tool but as soon as i turn the key off then on again it comes up again....
the code was p0700, po100 and p0143...i haved fixed all the problems with it, replaced the nss and everything works fine exept when the engine light its on the tranny wont shift into od(or 4th gear)
but when the light its off the tranny works just fine
i want to erase it so can get my trany to shift into 4th
thanks

MyNameIsNick

Take off the negative cable and let it sit for 15min. Worked for my Jeep and regularly for my car.

nico133

tryed that already...still nothing

freegdr

buy a book

freegdr

it has to be cleared by the scanner auto zone will read them for free then have them erase them you ow me a beer

Willys55

You have to clear the p0700 code from the tcu before you clear anyother codes. Another cause could be poor ground on the tcu preventing the code from being cleared

NJ-xj

Its not your jeep its your scanner. For some reason jeeps are really picky about there "doctors".

Jeeperisacreeper

I have that book and it doesn't say how to do it. I also tried letting it sit overnight with the battery unearth ans nothing happened (oh, it ran even crappier but nothing else) maybe it just don't work after '96?

Bustedknuckle

Just for kicks a giggles, try unplugging the Crank Position Sensor, then see if it'll scan. I've had Chrysler Jeeps before that wouldn't communicate with my scan tool due to a voltage issue from a sensor, and CPS being a common denominator, unplugging the sensor seems to remedy it. Especially if leaving it unplugged over night didn't prevail.

SeriousOffroad

Cart before the horse folks.
The OP doesn't state that he's repaired the problems being reported by the PCM.
P0100 is a Mass Air flow Sensor code, could be a typo by the OP (?)
P0143 is an O2 Sensor issue P0700 is a generic Tranny code.

As far as clearing the codes:
Disconnect the + and - cables from the battery.
Connect the + and - cables together for a minimum of 10 seconds.
Reconnect to the battery.

If the CEL is still on then you've still got probleems that need to be repaired.

nico133

well i took it to a friends transmission shop and told me 99% of the times the aw4 tranny will throw the po700 code because there is a bad or malfunctioning tps....aperantly the tps sends voltage to the transmission ecm and therefore not letting it shift from 3rd to 4th(since in the 97-01 aw4 3rd to 4th shifts are controled electonically)
so suggetsted changing the tps
im trying this tonite as its only $45
thanks guys
keep my fingers crossed

freegdr

if you clear the codes withthe vechicle not running they should go away intill restart yes

freegdr

page 6-22 bottom right corner

SeriousOffroad

Not true.
P0700 is a generic code that typically can be corrected by cleaning the contacts in the NSS.

Have you checked the O2 Sensor Fuse yet?

nico133

well i did change the o2 sensor but i never checked the fuse...i didnt even know that there was a fuse for it, where is in the fuse box?
man am i ever glad about this forum....i would been lost without it
thank everyone for the response...
i was doing some search and it seem like its a permanent cod e on the ecm....so regular odb2 scaners only erase memory...not pemanent codes....i have to find out how to?