Engine/Transmission (1998.5 - 2002) P0126 and P0237 codes. Help!

[Dave MacArthur]

Hello everyone,



Well my truck has started losing power occasionally and shows the above codes. Sometimes it runs fine and sometimes it feels like it's way down on power. Almost like there isn't even a turbo.



I'm the original owner and the only engine mod was done about 10 years ago. I installed an Edge Comp box at that time. However I never punched the pump wire so it's really running as an EZ box. I do remember there was an elbow that I replaced on the turbo I think. What was that for again?



It has about 105,000 miles on it now. It has the original lift pump.



Is it at all posible that it's a wiring issue or something? Or do I need an Injection Pump? Also, what's the latest on lift pumps these days?



Thanks for any help.

 

[Joe Mc]

https://www.turbodieselregister.com...ine-transmission-faq/96634-24v-code-list.html



This may help. I looked at the list and didn't see an 0126 code but did notice 0125 twice? Maybe the second one is the 0126.



Save the code list to your favorites for future reference.

 

[JLandry]

Dave,



Are you sure you don't mean P0216?



That P0237 DTC along with the symptoms you've been experiencing could be explained by a faulty MAP sensor. It's easy and inexpensive to replace, so I'd start there.



Please clarify on the other DTC.



Best regards,



John L.

 

[Dave MacArthur]

Sorry,

It is P0216. Dyslexia strikes again!

 

[Dave MacArthur]

If a moderator could fix the title, please do. It should read P0216 and P0237.

 

[JCyrbok]

start saving money for a new injection pump, your gonna need one sooner than later. Sorry.



J-

 

[JLandry]

Sorry,



It is P0216. Dyslexia strikes again!

OK... well the P0216 means the VP44 can't achieve the requested injection advance from the ECM. This is usually caused by internal VP44 wear, but it can be caused by low fuel pressure being supplied to the VP44. If you've verified adequate fuel pressure after the fuel filter, then it's safe to assume it's a problem with the VP44. Consider that P0216 as your early warning sign the VP44 is wearing out. My own truck's VP44 starting throwing the P0216 DTC this year and it has 110,000 miles on the original. I plan to replace it in the next couple of months. I can afford to wait because I don't drive it very much this time of year.



In the mean time, I'd replace the MAP sensor and see if it helps.



Good luck,



John L.

 

[Dave MacArthur]

I haven't checked anything yet. I have no idea what the fuel pressure is. So does that mean that it's possible that it's the lift pump? Or is it definitely the VP44?

It runs fine about 1/2 or more of the time. Plenty of power.

Can someone tell me how to check the fuel pressure or provide a link?

 

[JLandry]

I have no idea what the fuel pressure is. So does that mean that it's possible that it's the lift pump? Or is it definitely the VP44?

Before you do *anything* else (even drive the truck again), check the fuel pressure first!!! Running with low fuel pressure can ruin the VP44 in short order. With a lift pump that old and that P0216 DTC, you may indeed have low fuel pressure now.

Can someone tell me how to check the fuel pressure or provide a link?

Start by getting yourself a fuel pressure test kit. Inexpensive versions for about $25 are available at places like Harbor Freight Tools and eBay. Your local auto parts store will also have one, but likely you'll pay more.



The best place to take a measurement is at the fuel line inlet on the VP44. My 2001 has a Schraider valve at this spot (it looks like a short tire valve stem) which most fuel pressure test kits are designed to connect directly to. If your's doesn't you'll need an adapter fitting available at various online retailers (like Geno's, etc. ).



The minimum acceptable fuel pressure under any condition is 5 psi. Above 15 psi at idle is an ideal minimum. Various engine loads will result in fuel pressures somewhere in between.



If you do find low fuel pressure, change the fuel filter and then retest. If still low, then the lift pump needs to be replaced.



Longer term you need a fuel pressure gauge in the cab so you can monitor the fuel pressure continuously.



Best regards,



John L.

 

[Dave MacArthur]

Thanks everyone. I'll report back after I check the fuel pressure.

No matter what, I guess I should at least replace the lift pump. What's the latest info on which one to go with?

Thanks again,

Dave.

 

[JLandry]

What's the latest info on which one to go with?

Dave,



Be ready... You're likely going to get a lot of strong opinions.



To start with, I think almost everyone will agree you don't want to go with a another stock Carter lift pump. They just don't seem to put out good pressure and often don't last long.



I've been using an Airtex gearotor type lift pump for a couple of years now mounted in the stock lift pump location (on the side of the engine) and I'm very happy with it. It's a direct replacement for the OEM pump with a simple no-mod installation. As to performance, my truck's fuel pressure typically shows 18 psi at idle (sometimes higher with warm fuel) and never drops below about 8-10 psi at full throttle / heavy load / high rpms. Highway cruise fuel pressure when towing my heavy travel trailer runs about 13 psi. At a typical street price of around $160, it's a great value and about the same cost as the stock Carter lift pump.



Of course there are much more expensive and elaborate lift pump / fuel filtration systems available, but I couldn't justify the added cost for my otherwise stock engine. When you start hearing about these more expensive systems putting out 25+ psi, remember that anything above 5 psi at the VP44 inlet (under all operating conditions) is adequate.



Just one man's opinion!



Good luck,



John L.

 

[Dave MacArthur]

Thanks John. I just ordered one from them along with their Fuel Pressure test kit. I'll install an in-cab gauge as well soon.

 

[Ram4Sam]

Dave,



Be ready... You're likely going to get a lot of strong opinions.



To start with, I think almost everyone will agree you don't want to go with a another stock Carter lift pump. They just don't seem to put out good pressure and often don't last long.



I've been using an Airtex gearotor type lift pump for a couple of years now mounted in the stock lift pump location (on the side of the engine) and I'm very happy with it. It's a direct replacement for the OEM pump with a simple no-mod installation. As to performance, my truck's fuel pressure typically shows 18 psi at idle (sometimes higher with warm fuel) and never drops below about 8-10 psi at full throttle / heavy load / high rpms. Highway cruise fuel pressure when towing my heavy travel trailer runs about 13 psi. At a typical street price of around $160, it's a great value and about the same cost as the stock Carter lift pump.



Of course there are much more expensive and elaborate lift pump / fuel filtration systems available, but I couldn't justify the added cost for my otherwise stock engine. When you start hearing about these more expensive systems putting out 25+ psi, remember that anything above 5 psi at the VP44 inlet (under all operating conditions) is adequate.



Just one man's opinion!



Good luck,



John L.

John, does that pump eliminate one or both of the banjo fittings?



Sam

 

[JLandry]

John, does that pump eliminate one or both of the banjo fittings?

No... it uses the stock fuel fittings on the truck.



Regards,



John L.