Hi. Was reading posts and read about limp mode but can't find a thread that says how to confirm it.

Does limp mode apply to the tranny or diesel? I have no CEL or stored codes.

Tack is not functioning properly most of the time, but that is another story.

When stopped and placed in drive or reverse, step on gas, diesel does not rev up to begin move. My truck crawls away from a start but once movng accelerates and shifts normally.

If this is a limp mode problem, how do I verify the limp mode condition is present?

Thanking anyone who has something I can check out.

 

Limp mode is when an engine or tranny will detune itself to prevent further damage. Engine limp mode is detune itself, less fuel going to it. I think. Tranny limp mode is usually locks out overdrive and/or 3rd also. You should have codes if any limp mode. Do the 3 cycle key for codes. You may have an apps problem also.
If no codes, disconnect both batteries for about 1/2hr. Reconnect and go for drive to see if anything changed.

 

Thanks for the reply. Did not know that both engine and tranny had limp modes. Tranny works good after vehicle gets moving. Third and O/D work.

Engine seems to have no power leaving from a stop. It won't rev up in gear to get the truck moving from a standstill, but once moving seems okay.

I have no codes, tried the key cycling, just get a "done" message. I have a scan tool and it shows no codes either.

I'll investigate a possible apps problem and have disconnected batteries like you suggested.

I also pulled the fuse tipm box out, took it apart to check out possible corrosion issues, but it looks clean.

Was wondering also if the TC was locking up in first right away once the truck begins to move? Would this be enough to make the engine feel like it has no power to accelerate the truck? Is there a way to distinguish TC lockup from engine limp mode to see which is causing the problem?

 

Limp mode causes the engine to de-fuel and it also makes it to where the transmission starts out in 2nd gear, locking out O/D.

If your tach doesn't work, and it takes a lot for the truck to get out of it's own way, your crank position sensor is at fault.

 

Okay, will check out, thanks.

Tack sits low most of time, works once in a while, sometimes operates like it has a mind of its own. It'll go into red line when shifting but there is no way the engine is turning that fast. It over reads and under reads.

When I do that code check with the trip button pushed in when the key turns on, all the gauges go to max except the tack whick reads zero. Then the speedo drops a few increments, then when the speedo drops to 40 km/h the tack goes to max, then next speedo drop they all go to zero (I think if my mem is right.) The trip codes were:

S 125
. 283
C 447 and
HR 3283

Does that mean anything?

 

How did you obtain the codes?

 

That test is for instrument cluster only. Engine codes you will need a scanner and connect to the diagnostics port under the dash

 

The Data Link Connector (DLC) (3) is a 16-way molded plastic connector insulator on a dedicated take out of the instrument panel wire harness. This connector is located at the lower edge of the instrument panel, outboard of the steering column. The connector insulator is retained by integral snap features within a rectangular cutout in the lower instrument panel reinforcement (2), just below the lower edge of the instrument panel steering column opening cover (1).

Some auto parts stores will read code for you for free. 2006 trucks are CAN-C bus.

 

Try the key cycle. Turn your key to on, then cycle it to off an on 3 times. Try not to hit the starter in the process. You will either see ------ or PXXXX a few times. ------ mean no codes, and obviously PXXXX means you do. Have to be kinda fast at writing them down, and when it's finished, d0nE will appear. If you goofed up, start the truck and let idle for a few seconds, then try the key trick again.

 

Hi. Yeah I put a code reader on the diag port and got no codes. The instrument cluster codes - do you know what these mean, if anything?

I saw a youtube video about a cluster replacement and when the fellow was finished he tested it. The test was kind of neat, all the gauges went to max, all lights on. Then the speedo decreased 10 mph or 10 km/h until it hit 60, then the tach followed it down 10 at a time. The other gauges joined in at 40 and went down 1/4 notch at a time. Not sure if this a dodge cluster or a remanufactured one as the dodge clusters seem to have many problems too.

 

The cluster codes that you gave are not valid. Try it again. After the gauges and light test you will see C-CODE in the odometer. Then the codes will show in the format something like XX YY. The first two digits will be the code and the second two will be the number of times it has happened. Then you will see DONE and everything goes back to normal.