No Power on Launch

[WM-300]

I have a 2003/2500, HO, 6 Speed with 4. 10 diff's



On Launch I have no power. The truck slowly (limps)climbs to 23 miles per hour on the speedo, then it wakes up and climbs in speed fast as it always has done. This issue is not RPM related as you and wind her right out on launch, but not until 23 MPH does she wake up.



Slow down below 23, downshift, mash the go pedal and its dead until the truck gets to 23 mph.



I pulled my gooseneck trailer last week with 6600 pounds on her. No

problem on launch... ... just very slow until it reaches 23 mph, then I am gone.



Any thoughts



wm300

 

[cerberusiam]

Are you saying your engine is taching at 2700 or higher rpms and the truck is not moving well until you get to 23 mph?



I find that hard to believe but its possible if the clutch is failing.

 

[GCroyle]

I find that hard to believe but its possible if the clutch is failing.

Following up on cerberusian's theory, two additional comments.

1. Tach and MPH are syncronized or in unison with a clutch that IS NOT slipping. If RPM spikes and MPH is not keeping up, slippage.

2. Smell anything nasty during these acceleration runs? If you are really slipping the clutch, people behind you might even notice the smell.

 

[WM-300]

The clutch is not slipping. I have had manual transmission cars/trucks for 55 years. I know what a slipping clutch is like. Even pulling my goosnecks with a truck on it, not any indication of a clutch problem. Seems like 23 mph is the key tot he problem. If I drop my speed to 25, down shift and mash it, All is normal. Go below 23 and she is dead.



WM-300

 

[WM-300]

I had to go to the village. To get home I have to climb a 1800 foot mountain on a twisting dirt road. I tried all sorts of things. with out question the coming alive at 23 mph is real and totally reproduce able.



I am wondering if there is any speed sensor that could be failing that gives the computer bad data. The computer gets data the engine is to slow to fuel heavy or it thinks at that speed there is not enough boost for heavy fuel.



My truck is bone stock, no boost gauge so I can not give you a pre/post 23 mph boost number



wm300

 

[cerberusiam]

AFAIK, the only speed controls related to engine performance are rpm limit of 2100 at less than 5 mph on an auto (not sure if that applies on a manual), and, 110 mph speed limiter.



If it is dead in the bottom end a bad MAP sensor could be the issue, or, APPS starting to fail. Without gauges it is tought ot tell whether it is boost not rising of fuel lacking.



What does the tach read when it wants to run correctly and does that correlate to speed?

 

[AH64ID]

Is it 23 mph in any gear?

 

[WM-300]

To answer the last 2 posts;

Yes, 23 mph in any gear.

When it wakes up the tach is roughly 2200 rpm's

Its like its not getting fuel. Tach comes up to 2200 roughly and no matter how much more you push he go pedal, it climbs very slow until the speed is 23 mph on the speedo. And at the same time the tach is also climbing very slow. Then it wakes up and flys.

What is APPS Starting to fail. Will it leave me high and dry in a total fail

Thanks for all your help

wm-300

 

[cerberusiam]

APPS completly failing is rare but they can sure make driving a challenge, if that is what it is.



It sounds suspiciously like the ECU is not seeing the correct wheel speed until 23 mph and derating the power.



Have you had it scanned for codes? Any CEL's set? Any flashes at a dealer lately?

 

[WM-300]

APPS completly failing is rare but they can sure make driving a challenge, if that is what it is.



It sounds suspiciously like the ECU is not seeing the correct wheel speed until 23 mph and derating the power.



Have you had it scanned for codes? Any CEL's set? Any flashes at a dealer lately?

I have not yet had it scanned for codes. I know a person that has a scanner. I will get it scanned. No flashes since 2003 when I bought it. What is APPS ? What is CEL's



wm300

 

[cerberusiam]

APPS - accelerator pedal position sensor



CEL - check engine light



You can do the key-on key-off 3 times in 5 seconds and the codes will display in the odometer window.



I assume you have changed fuel and air filter to rule them out?

 

[WM-300]

APPS - accelerator pedal position sensor



CEL - check engine light



You can do the key-on key-off 3 times in 5 seconds and the codes will display in the odometer window.



I assume you have changed fuel and air filter to rule them out?

Ok on the CEL, It has never come on.

Ok on checking the codes with key switch. I will check them and report back here late tomorrow afternoon.

The fuel and air filter were changed 3 weeks ago when I changed oil



Thanks for your continued help



WM-300

 

[AH64ID]

While it's most likely not your issue, it wouldn't hurt to get a flash. If you can find someone local with a Smarty you can get updated to the latest OEM software in the time it takes to drink a few beers.

I have found a TSB or 2 talking about off idle performance, mostly auto's but you never know.

 

[Prairie Dog]

A few beers? I'd have a hard time swilling one down in that little amount of time. Remind me to buy more beer if you come over John (or hide what I have) #ad
:-laf

 

[AH64ID]

Well, being from Duvall I know where Bothell is. . your beer may not be safe

 

[WM-300]

Update on the No Power on Launch;



I did the key flip this morning and got two codes'



P0633 Skim Key not programmed in ECU. I have searched and cant find much. My truck has no security system, just a plain old key, nothing special.



P0602 Control Module Program Error. Again < idont understand. My truck has never been programmed since 2003. This problem just started 2 weeks ago.



I apologize for not being able to do more searching on the forum for answers, I am sure they are there. I live very remote in the mountains and my internet connection is DIAL UP with a connection speed of 24. 4K. It takes almost a minute just to bring up a new page. SO please be patient and go easy on me. I am lucky just to

have Dial Tone LOL



wm300

 

[cerberusiam]

Dial up definitely makes searching a challenge.



The skim key error is just a nuisance and could be triggered by the other one.



IIRC, the P0602 is an ECU death code. Basically reflash the ECU with a new load and if it comes back replace the ECU.



That said, battery condition, battery connections, ground connections, etc, can trigger some of these codes. Since you have an 03 and htye have the potential for corrosion in the ECU A & B connectors ther eis another place to check.



Programmers will also throw this code if they do not completely upload correctly. If you have no programmer and it just started then its likely an ECU issue. However, try the other easy stuff first. Good luck.

 

[WM-300]

Dial up definitely makes searching a challenge.



The skim key error is just a nuisance and could be triggered by the other one.



IIRC, the P0602 is an ECU death code. Basically reflash the ECU with a new load and if it comes back replace the ECU.



That said, battery condition, battery connections, ground connections, etc, can trigger some of these codes. Since you have an 03 and htye have the potential for corrosion in the ECU A & B connectors ther eis another place to check.



Programmers will also throw this code if they do not completely upload correctly. If you have no programmer and it just started then its likely an ECU issue. However, try the other easy stuff first. Good luck.

Ok, thank you. A few questions



1. Being remote as I am, I woudl guess the Dodge Dealer abotu 60 miles from here is the only place to get a ECU flash. I dont know anyone that has a programmer or CTD for that matter.



2. Where is the ECU and connectors A&B located so I can clean the contacts. Other than battery terminals, any other suggestions on connectors to clean ?



3. If its a dirty connector or the flash works will the P0602 code clear by its self



4. Is Dodge the only place to buy a new ECU. ROugh idea of the ECU cost ?



Thanks

8Valve

 

[cerberusiam]

ECU is on the driver side of engine just above the oil pan rail about mid block. Connecters can be reached from top or by removing the driver side fender liner.



The code will not clear until it is cleared by a capable programmer. It will go dormant and not cuas eissues if the source is found.



Dealer is obnoxiuosly expensive for an ECU. You want one of the ECU rebuilder places for $700-$800 exchange. New list price is like $2200 for an ECU.

 

[Mark31]

WM, I got an ad in the mail today from Dish: $39. 95 a month for 5 years for satellite internet. It's not Roadrunner speed, but it's not rigor mortis dial-up either. 1-888-825-2581