The dealership or shop that replaced the CTM should have known this but through lack of communication it was overlooked by the technician that took the work order.

 

OK ... so now I have a new problem. When I was driving on cruise control down interstate at 70-75 mph all of a sudden check engine light comes on and kicks it off cruise (which I am assuming is because the computer detected a fault and kicked it off as a safety feature). Anyway, once I got down to a 1/4 tank of gas the truck starts surging like transmission is slipping but it doesn't surge when I put my foot into it and put the engine under a load. Any ideas for a quick and easy fix????

 

First thing to do would be to check for trouble codes. Turn the ignition key from off to run and back to off 3 times, and on the third time leave it in the run position. Any codes you have stored will display in the odometer. There is a list of the codes and what they mean up in the sticky topics at the top of the Second Gen page.

I have no idea how the fuel level could cause a problem like that unless the fuel pump is bad and somehow starves for fuel when the fuel level in the tank is low. You may want to check the fuel pressure, you can get a good but cheap fuel pressure gauge kit at Harbor Freight. Fuel pressure at idle should be between 47 and 51 or 52 psi. When you turn the truck off, leave the gauge connected and if the pressure drops below 30 in less than 5 minutes then the fuel pressure regulator is bad. The only way to fix it is to replace the fuel pump, the regulator is built into the pump assembly.

Check for codes first, that is the best way to begin the diagnosis.

Jimmy

 

Thanks Jimmy, I will check for stored codes in the morning.

 

OK ... checked the codes and I am getting P0204 and P0121. I know 0204 has to do with the #4 injector and 0121 has to do with TPS voltage, but that is the extent of my knowledge. Help!?!?!

 

Picking out one little thing here, which may take you off course, but might help; so use with a grain of salt.

This sounds like the TPS (Throttle Position Sensor). It can be an intermittent (not constant) problem until replaced.

My $,02

 

Well it sounds like a bad injector to me. The injectors have constant 12 volts when the key is on and in the run position. The PCM switches ground inputs to each injector in a sequential order, so I doubt the PCM is bad. The #4 injector is the one in the middle on the right side of the engine on a V6, or it is the second from the right on a V8. I don't know which one it is if you have a 4.7. You may need to replace the injector to fix the problem, and it would not hurt at all to have a fuel induction service done to help clean out all of the injectors and the rest of fuel system too. Professional services like BG or Everwear work very well, most tire shops and garages will do one or the other of those. There is also a DIY fuel service kit made by 3M that you can buy at parts stores, it costs about $30.00. I don't know how well it might work though, I have never used it and don't know anyone who has.

The TPS is easy enough to change. It is on the left side of the throttle body. It is only held in place with two torx screws. If it were my truck I would use a good quality part like Echlin (Napa) for replacement of the TPS.

Once you get the injector and TPS replaced, you can either stop at a parts store and ask if they will clear the trouble codes for you or you can do a hard reset on the PCM yourself by disconnecting the negative battery cable and holding the ignition key in the start position for 30 seconds. This will clear all codes from the PCM, and you will need to drive the truck for a few miles so the PCM can learn and set itself for the new TPS. It should be done in probably less than 20 miles worth of driving.

Both the injector and TPS problems can cause the cruise and throttle problems you were having with the truck. If it has not been done already or if you do not have the maintenance history on the truck it might be good to go ahead and do a full tune-up with new plugs, wires, cap and rotor. The Belden Premium wire set from Napa is very good quality, it is every bit as good and better than OEM and is much better than the cheapie $20.00 wires you can get at other parts stores. The cap and rotor from Napa with brass contacts, part numbers MO26 and MO28 work great and last a long time. They are also made by Echlin and are very high quality. There are different opinions on plugs, personally I like NGK plain copper core plugs. They work great and are only about $2.00 each at Napa.

Jimmy

 

Jimmy, your Dakota's... whats... are very sensitive? (What things *belonging to a Dakota, or your Dakota,* that are supposedly sentitive, did you mean to be referring to?)

Mike