my service 4wd light came on

[mikelikefish]

I drive a 2004 dodge ram 2500 5.9 diesel the light came on any suggestions as too what it could be . If someone with a similar experience could suggest a option or two
Thanks

[tri777]

activate on/off a couple times to see of it goes out,if not crawl under it a snoop around for anything obvious..when's last times fluid was changed?

[harrydude]

I will go with loose wire conections at transfer case. Plastic clip breaks and a zip tie fixed

[rugatika]

I've found the main reason for those lights coming on is so the dealership can charge you 100 bucks to reset the light and tell you nothing is wrong. Quite handy actually.

[Taco]

Originally Posted by rugatika

I've found the main reason for those lights coming on is so the dealership can charge you 100 bucks to reset the light and tell you nothing is wrong. Quite handy actually.

40 bucks for a princess auto code reader and you can read and clear codes yourself

[megadodge]

$15 for a blutooth odb2 reader that you can sync with your smart phone.

As for the error code - with all of the snow lately, could be a flaky wheel speed sensor.

[Rockman]

Google it. Often those codes mean your oil change is due, or some such whatever. Any decent dealer would clear it (without checking) for free. For them to run the scanner on it and tell you what it is, that's what costs you.

Check your vehicle mileage for whatever service is due, and other than that, consider if your oil change is due. It's probably one of those.

Lastly, you can reset those codes yourself in some cars without getting into wiring or having any machine or reader. Google it (for your truck specifically)

[Rockman]

PS: If it is an important longer-term service, you may want to know that and do it, as regular maintenance is important...

[rugatika]

Originally Posted by Taco

40 bucks for a princess auto code reader and you can read and clear codes yourself

Roger that...got one several years ago.

[Muskeg]

Check Abs wiring harness. I had issues with my Tundra and found wires broken at sensor from excessive mud build up. I had traction control light on also though. Not sure about Dodge

[rugatika]

Originally Posted by Muskeg

Check Abs wiring harness. I had issues with my Tundra and found wires broken at sensor from excessive mud build up. I had traction control light on also though. Not sure about Dodge

Same thing happened to my Tacoma. And I like it! Lots of purdy lights in the dash and no pesky traction control coming on. My abs harness can be found dilligently taped to my axle...not connected to anything. The way God meant.

[TBD]

can be "duly" ignored.

Just an auto industry scam.

[Mike_W]

Does it only come on when in 4x4? Does it actually engage into 4x4?

[Wanderingwest]

On the grand Cherokees of similar era, there is a good chance its the sensor for the front axle 4x4 engagement. I have the same thing on my 06 wk. I know there was a firmware update for the grand Cherokee computers regarding this, it is a known problem, but not enough for a recall.

[javlin101]

Had the service engine soon come on with my 2009 Pathfinder. CT had code readers on for 1/2 price so bought one and got the code. Turn out to be the EVA valve. Talk to a Nissan mechanic on Justanswers.com and he informed me that this is for emissions check and if I do not replace it the worst thing that could happen is the vehicle will not pass emissions test for my State. so I cleared the code and moved on.

Code reader - $53.00 reads codes on domestic and foreign 1996 and newer.
Justanwser.com - $29.00

The eva unit is tucked up between the frame rail and the rear quarter panel. wonder how much it would have cost to do that unnecessary repair. The valve it self from an after market supplier was around $100.00.

Buy a code reader!

[Big_Willy]

I had a "Service 4WD" light come on with my 2002 Chev Avalanche. Avalanche had about 200K on the clock at the time, so, it was not as if it owed me anything.

I tried a consumer grade code reader, but, it was not very informative.

So, being a handy guy, I just started replacing likely suspect parts myself.

Replaced;

-Transfer Case Motor which mechanically switches gears on transfer case

-Transfer Case Sensor (part of above assembly)

-4WD Selector Switch (in dash)

-Grounding Wires (on frame)

-WeatherPak connectors (cleaned, checked and re-installed)

None of the above actions solved the issue, but, in total cost me less than $250.00 and some of my spare time.

So, I finally broke down and took my truck to the local mechanic for advanced diagnostics. At first, he was also stumped as I had eliminated alot of possibilities. But, his advanced scan tools did pick up high resistance in the Transfer Case Controller which is buried behind the dash.

Said part was replaced with a certified re-built for $100 and problem solved. Labour was about $150.

For the remainder of my time with that truck the Service 4WD light never came back on again. $500 well invested in my books.

Moral of my story is diagnostics are key. If you have the ability and patience, you can be your own mechanic and may luck-out. But, the guys with tens of thousands of dollars worth of tools can save you lots of time and aggrevation, especially if your truck is key to your livelihood.


-Willy