"Low Range" light?
Senior Member
Joined: Nov 2008
Posts: 230
Likes: 0
you CAN NOT switch from 4H to 4lo without putting it in nutral atleast with the floor shifter, it uses a totally different set of gears in the transfer case and if your in drive when you shift you will blow all the gears up. if your truck is letting you shift into 4l0 in drive there is something electrically wrong with it. with the floor shifter you physically can not move it from 4hi to 4lo without it in nutral.
Junior Member
Joined: May 2018
Posts: 1
Likes: 0
H
Hold the phone here!
Do not assume it's a "correct asumption" to be able to shift into 4L as you had experieced, unless there is a possible fault present.
Reason:
The GEM modual 'requires' three signals as 'holdoff' protection before entering 4L.
They are a brake pedal signal.
A TR. selector neutral position signal.
A no speed signal from the PCM.
Reference user manuel pages 181-182.
.
Primary reasons are the huge difference in gear reduction that takes place may cause accident or injury to passengers, inside loose articles shifting, damage to transmission/drive train, loss of vehichle control and a large change in the shift program.
Example; think of what it would it be like is this could happen at 50 mph on pavment, gravel or slick road surfaces ; each could result in a different outcome.
Do not think for a minute that FMOCO would want libility problems from such results and therefore has built in the protections against 4L engagement.
Not to mention insurance companies libilities from such results would not stand for ''no protection' being built in.
Even cruise control has several ways to disengage as protection the motor does not add a runaway condition or add to panic braking reaction causing accident.
The torque convertor even unlocks at brake application to 'reduce' some of the motor's forward drive at the same time panic braking is needed.
You are free to disagree but these are the facts.
Do not assume it's a "correct asumption" to be able to shift into 4L as you had experieced, unless there is a possible fault present.
Reason:
The GEM modual 'requires' three signals as 'holdoff' protection before entering 4L.
They are a brake pedal signal.
A TR. selector neutral position signal.
A no speed signal from the PCM.
Reference user manuel pages 181-182.
.
Primary reasons are the huge difference in gear reduction that takes place may cause accident or injury to passengers, inside loose articles shifting, damage to transmission/drive train, loss of vehichle control and a large change in the shift program.
Example; think of what it would it be like is this could happen at 50 mph on pavment, gravel or slick road surfaces ; each could result in a different outcome.
Do not think for a minute that FMOCO would want libility problems from such results and therefore has built in the protections against 4L engagement.
Not to mention insurance companies libilities from such results would not stand for ''no protection' being built in.
Even cruise control has several ways to disengage as protection the motor does not add a runaway condition or add to panic braking reaction causing accident.
The torque convertor even unlocks at brake application to 'reduce' some of the motor's forward drive at the same time panic braking is needed.
You are free to disagree but these are the facts.
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
ok so i have an 02 f150 concerning the shift into 4x4 on the fly, in my manual it says u can shift on the fly but at a speed no faster than 15mph into and out of 4 high. But not 4 low, with this it said to stop first. And i tested this last winter when we got snow and roads iced up.
Member
Joined: Jan 2018
Posts: 66
Likes: 0
ok so i have an 02 f150 concerning the shift into 4x4 on the fly, in my manual it says u can shift on the fly but at a speed no faster than 15mph into and out of 4 high. But not 4 low, with this it said to stop first. And i tested this last winter when we got snow and roads iced up.
You reopened a post that has been closed for almost 8 years.
2HI and 4HI are the same gear ratios, you should be able to go into 4HI at any speed, assuming proper road surface at the time you are making the change. 4LO is another matter. You should come to a full stop, or at least a very low speed, to change into 4LO.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
In the 2002 Owner Manual, bottom page 179.
Heading; shifting 4H to 4L.
Bring vehicle to stop.
Depress Brakes.
Place gearshift in Neutral.
Move shift Lever through Neutral to 4L and hold until fully engaged. This could take as long as 15 seconds if any parts of the drive train offer resistance to operating.
Remember that 4L involves a gear change 'into' the total drive line that is not Synchronized by internal means,...…. for that function.
Good luck.
Heading; shifting 4H to 4L.
Bring vehicle to stop.
Depress Brakes.
Place gearshift in Neutral.
Move shift Lever through Neutral to 4L and hold until fully engaged. This could take as long as 15 seconds if any parts of the drive train offer resistance to operating.
Remember that 4L involves a gear change 'into' the total drive line that is not Synchronized by internal means,...…. for that function.
Good luck.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
If you have ever put the transmission in 4L, you should know how it feels.
The gear ratio becomes very low. Can't miss this, and steering becomes hard making a turn.
.
Are you saying just the light comes on?
If yes, it's an electrical issue.
The light normally only comes on when the case motor goes to the 4L position and sends the signal back to the control module.
You have to provide more info than what little you provided.
The gear ratio becomes very low. Can't miss this, and steering becomes hard making a turn.
.
Are you saying just the light comes on?
If yes, it's an electrical issue.
The light normally only comes on when the case motor goes to the 4L position and sends the signal back to the control module.
You have to provide more info than what little you provided.
