Jump to content
  • Welcome To Mopar1973Man.Com

    We can see that your guest and been lurking about. When you register on the Mopar1973Man.Com site you'll be able to interact with all the other members. This is the most friendliest Cummins forum you'll ever join. Take the time right now and  REGISTER  on the Mopar1973Man.Com this will open up many more options and functions on the website. Everyone is very friendly and helpful just ask questions and everyone will help you out the best they can. 

Recommended Posts

Can a failed or failing MAP sensor cause my truck to be very sluggish down low and continuously the P0234 code? 

 

I once upon a time had an edge ez but it’s gone now. The boost elbow that came with it is still installed though. I have a fass lift pump and a FP gauge. Otherwise all stock. Truck feels like a total pig off the line and doesn’t feel like it starts making any power until 1800 rpm or so. Also has trouble holding highway speed in OD on any hills even empty. 

Share this post


Link to post
Share on other sites
3 minutes ago, Me78569 said:

Our trucks are fueled based on map input.  A failed map will result in nearly no fuel.

Okay I’m somewhat happy to hear that. Is there a way I can definitively condemn the MAP or should I just go ahead and replace it? 

Share this post


Link to post
Share on other sites
9 minutes ago, Me78569 said:

have you looked at the troubleshooting article for that code?  

 

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/51_engine/obdii-error-codes_94/

 

 

 

 

Yes I have. Maybe I’m interpreting it wrong but I don’t get how that proves whether the MAP is good or not. Even with a stuck wastegate and totally stock fueling shouldn’t it not exceed boost limits? That article says to replace the wastegate and mentions nothing of the MAP sensor itself needing replacement. Is it just a part that never fails and if it had codes it’s pointing towards other parts being the cause? 

Share this post


Link to post
Share on other sites

You also should remove the boost elbow or close it all the way. Anything over 20 or so psi will set the the 234 code.My MAP sensor crapped the bed not long ago with the same symptoms. Had to make big runs at the hills just o get over them. The MAP is a $100 to $200 sensor so some trouble shooting would not hurt. The only place that had it in mine was Oriellys and they just happened to be the cheapest at about $105. 

3 minutes ago, skyhigh4by said:

Yes I have. Maybe I’m interpreting it wrong but I don’t get how that proves whether the MAP is good or not. Even with a stuck wastegate and totally stock fueling shouldn’t it not exceed boost limits? That article says to replace the wastegate and mentions nothing of the MAP sensor itself needing replacement. Is it just a part that never fails and if it had codes it’s pointing towards other parts being the cause? 

You will exceed boost pressures with a stuck waste gate. Thats why the waste gate is there. It opens near 20 psi if it is the stock one. But if it is stuck closed you will exceed the 20 or 22 psi to throw the code. I take you do not have a boost gauge.

Share this post


Link to post
Share on other sites

very true.  

 

follow the multimeter troubleshooting in the article it will tell you if the map is reading 0 psi at idle or if it is reading max at idle setting the p0234. 

 

unless you are driving WOT all the time then I would not expect an overboost code all the time just because of the elbow though.

Share this post


Link to post
Share on other sites
Posted (edited)

I don’t have a boost gauge. It’s one of many many things on the to do list. I very rarely go beyond 3/4 throttle. The low power problem feels like it’s a somewhat recent thing I don’t remember it being so gutless and it almost feels as if it’s slowly getting worse. The VP has maybe 20k miles. Truck has under 120k miles. 

 

I guess i will will try to see if the wastegate is stuck. The boost elbow isn’t adjustable and I don’t think I have the stock piece around. 

Edited by skyhigh4by

Share this post


Link to post
Share on other sites
Posted (edited)

Probe the map sensor output wire, pin c of the sensor, using a multimeter at Idle state.  The Sensor should be outputting near 4.5v.  anything more than .25 less than that means your map sensor is reading boost at idle.  If it reads .5v at idle then you will trip a code p0237, but if it reads ~4v-1v at idle then you will get this p0234 code.  

 

effectively means the map sensor is stuck reading a single psi reading and not functioning.

Edited by Me78569
  • Thanks 1

Share this post


Link to post
Share on other sites

I have an aftermarket waste gate actuator, Banks Big head, It opens near 33 psi. When the Banks tuner crapped out I drove it for 3 years before getting the comp. Towing or not I had to drive it by the boost gauge to keep from setting the code or the engine defueling. I also had RV 275's which will push the boost up more.

5 minutes ago, skyhigh4by said:

I don’t have a boost gauge. It’s one of many many things on the to do list. I very rarely go beyond 3/4 throttle. The low power problem feels like it’s a somewhat recent thing I don’t remember it being so gutless and it almost feels as if it’s slowly getting worse. The VP has maybe 20k miles. Truck has under 120k miles. 

 

I guess i will will try to see if the wastegate is stuck. The boost elbow isn’t adjustable and I don’t think I have the stock piece around. 

When my map was failing I had a scan gauge II hooked up and when the problem would occur, just like what you are experiencing, the SCII would see 14.6 psi on the MAP and never move. I did get to hook it up to a Snap on Versus and read 0. that is how I determined mine was bad. Mine was doing the same as yours, just pain gutless.

 

 

Share this post


Link to post
Share on other sites

Okay thanks. I have a scan gauge I could hook up and an OTC genesys I can watch live data with so I’ll check into that. 

Share this post


Link to post
Share on other sites

I agree. Mine read whacky numbers for boost. The 14.6 reading was the SG version of zero. The Snap on read 0. Neither of them moved while driving. A new sensor did fix my issues. 

 

To the OP, whule sensor did fix mine it still could be wiring issue. I rolled the dice and won.

Share this post


Link to post
Share on other sites

you dont need to see exact numbers, what you are looking for is it reads something steady at idle, then it increases with load to a poin that makes sense.

Share this post


Link to post
Share on other sites
2 hours ago, Me78569 said:

you dont need to see exact numbers, what you are looking for is it reads something steady at idle, then it increases with load to a poin that makes sense.

My SGII would do that when the sensor was working but at wierd numbers. I idled around 27 psi and WOT around 34 psi. But it did rise and fall like it should until the sensor failed.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...