- Reply to Topic
Thread: Bizarre malfunctions after using code scanner Reply to Thread
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
10-14-2019 12:22 PM
99wjtx A leaking brake booster, maybe or otherwise a vacuum leak somewhere. The brake booster is vacuum-powered. There's a rubber diaphragm in there that eventually fatigues and springs a leak. It has happened to many here on the forum with higher mileage WJs. As the tear eventually gets larger, the vacuum-assist of the power brakes will begin to diminish and the brake pedal will become progressively harder to press.
10-14-2019 09:49 AM
djs99 Hallelujah!!! 99wjtx that did the trick! Saved me an embarrassing trip to my mechanic. I am so grateful that these forums exist. Thank you for taking time to respond.

Now I have to figure out why there is a squealing/whistling sound coming from what seems like the brake pedal when I am driving even when accelerating, all I have to do is tap brake pedal and the whistling goes away but comes back within minutes. I will create new post for this but does that sound like anything you're familiar with? not having any problem pressing pedal, and it does return to normal position. But before it started whistling it was making a whooshing sound like air escaping AFTER applying the pedal. That was replaced by this whistling sound like a calliope.

10-14-2019 09:14 AM
Mattyjm I know it must seem coincidental, but it's not. You have a broken wire in the boot that runs between your driver door and the door jamb. Pull back the black rubber boot and inspect the wiring for breaks or wear. That should solve your problems.
10-13-2019 03:38 PM
99wjtx Disconnect your battery for about 15 minutes (some say longer) to reset the BCM and PCM. See how things are after that.
10-13-2019 03:15 PM
Bizarre malfunctions after using code scanner

Something very strange just happened to my 1999 Grand Cherokee (V8, Limited). First let me give background on what was already known to need repair: (1) driver window not working prob the regulator; (2) high-pitch squeal often emanates from front right side, goes away if I tap on the brake; (3) horn & steering wheel controls not working, Ive already researched how to replace the clock spring; (4) rear left signal light not working but the bulb is fine.

I've been planning on replacing the clock spring and window regulator myself next month but still need to research the strange brake pedal sound. Anyways, this is background. Otherwise car was running fine.

Yesterday my gf's car (2008 Land Rover LR2) wouldnt start so I borrowed a cheap old code scanner from a neighbor to look for clues. Didnt find anything I didnt already know. Pulled up my Jeep to try jump starting her LR2 but that did not help (didnt think it was battery anyways). So I gave up. THEN I decided to see what codes the scanner would pull up from my Jeep, so I plugged it in and took a look - only code was a seat heater fuse, oh yeah the passenger seat heater not working anymore. OK, return the code reader, park the jeep, time to walk the dogs.

A few hours later, I hop in the Jeep to drive to a friend's house for dinner. First thing I notice - running lights dont flash when I use the key to remotely unlock the car. Get in the car, start it up ... hey, interior lights are all on and wont turn off! Check all doors - all are closed. Only way to turn off interior lights is to turn the dimmer switch all the way off, which also dims my dash, clock, etc. Then I notice the headlights will not turn on in Auto position, only when I switch to On position (I usually leave them set to Auto). And, the INFO DISPLAY has NO DATA - miles to empty, MPG, temperature, etc all just dashes. BUT the compass does work! And now I just realized that no windows work, fortunately they are all up, but the sunroof does work. My seat memory is still in place and works, and the radio presets are still there. All this happened after I tried to jump gf's car and then plugged in a code scanner under the dash.

Did the code scanner somehow do this? Was it from attaching jumper cables to the Land Rover? What the hell is going on and how do I fix this?

I thought I had my hands full with the repairs listed at top, but now I am really frustrated and hoping there is a simple "reset" for this.

Thanks for any suggestions!!!

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

For the best viewing experience please update your browser to Google Chrome