my Ranger has started doing something that is very odd...after this past weekend trans rebuild, in which the battery was unhooked for 6 days. on the test drive, trans worked AWESOME..then suddenly the ABS light and the OD light started flashing, trans went into "limp home"...talked with a couple buddies..and was told to, unhook battery[already had], then hook it up and turn key[nothing else] for at least 30 min, then start engine and let come up to temp before driving..ok did that, all worked great...except..now, it has a VERY unpredictable symptom..

driving along with all just fine, it does this "total dark/off" for everything..eng shuts off[sometimes fires right back up by itself]and speedo starts reading 0mph up to 30mph while sitting still... does this ranger now have a bad case of Alzheimers/Dementia? I have a theory, which is just that, a theory...last weekend when it did all of this, i have a "code reader" not diagnostic scanner, that i tried plugging in, which gave a "total" power off then back on and radio ejected a cd..

is there something with the anti-theft and radio causing this? it does have an aftermarket radio.... open to suggestions/better theory..

 

Was your code reader a OBD II complient device? Plugging in a code reader into the OBD II plug should not have caused a loss of power to the truck, unless the power feed going into the OBD plug is loose/faulty, and plugging in the reader aggravated it.

When a CD ejects, it usually does indicate the vehicle (or dash) lost power to the battery. When ever I'm doing electrical type work, I always disconnect one battery cable, and I can hear the radio CD motor buzz (trying to eject a CD). I found that a previous owner had left a Gloria Estefan CD in the radio when I disconnected the battery to install my e-fan.

Also, Im confused with the statement of the transmission going into "limp" mode. I know an engine ECU/PCM can do this for the engines basics pertaining to the fuel and timing, but what does the transmission do in the way of limp home mode?

I would check the health of the charging system. It sat for 6 days, so perhaps the battery had/has a bad cell, and won't fully charge. Have it bench tested, along with the alternator. Also check that any of the factory ground straps are tight; was one around the area of the transmission removed during its service and perhaps was not re-installed?

 

Hey Bucko...

Thanks for the response....to answer your questions... yes the code reader is for OBDII systems only. Far as the transmission going into "limp home" mode...generally, most all "E" automatic transmissions, have some form of this. When a serious fault is detected, the PCM will lock the trans into either, 2nd or 3rd gear the ranger's 5R55E, happens to be 3rd gear. If the fault is an electrical problem, usually limp mode can be reset by disconnecting battery power, although it has the chance of doing this again.

My truck's charging system, is functioning properly with no issues, although the battery is an "autocraft" or as i call them and the 'everstart' wal-mart batteries, a "neverstart" brand. It seems, every single zero-turn lawnmower i get in shop that won't start is because of these battery brands...hence the "neverstart"..LOL

I did raise truck on lift and inspect everywhere for the possible pinched or loose wire, with nothing found..There was/is a single ground strap from driver's side firewall to the cylinder head of engine that was slightly loose..Tightened that up, same unpredictable problem..

Update:..the unpredictable problem ALWAYS occurred with the radio off. Weds night when the event occurred again, i turned the radio on...Has yet, to happen again...Time will tell. I will post results if or if not happens.

 

Thanks for the transmission information. I was unaware that the PCM would lock them from a certain gear change; it makes sense!

A radio being off is causing the problem? Is it the stock radio, or an aftermarket one? Either way, that sounds strange as well.

There was a post sometime back on another site that talked about batteries, and those sold by walmart. I forget the manufacturer for their brand, but it was a well known one, at at one time, they had the Consumers reports "best buy" rating; then they got bought out, and the quality dropped significantly.

I've always had great luck with the motorcraft battery. My 2005 Ford F 150 had over 134K before I traded it in, and was on its second motorcraft battery. My current rides, a 2011 Mustang with 60K and my 2000 Ranger with 213K both have the motorcraft, and no issues with either yet. The Mustang still has its original battery, but the Ranger I'm sure has had it replaced a few times (I'm the third owner).

 

update..day 2 with no incident...all is working normal/great on Ranger...since turning the radio[aftermarket] on. i cannot explain this either..but for now, i'm going with: "somebody gave the gremlin water and kept him awake after midnight".. electronic functions/controls are GREAT...when everything works normally...however when they don't...get that jose' cuervo tequila bottle off top of fridge.