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Hello all I am new to this and hope someone can help. I have a 2000 7.3 and am getting code p0236 and cannot get it to go away. This is what I have done. I have sent in and had ecm and idm checked and idm rebuilt. Ecm check good and all latest updates. Last owner said he had it replaced some time back. R&r map sensor and tubes. Ohmed all wires from map to ecu and check out good. All fuses are good and do not blow. Get the wait to start light and all other lights come on when key is on eng. off. Now here is the kicker. I work for a city so we have a modis, verus d10, and apollo d8 snap on scanners. So when I check in memory codes I here a click in the dash and shows the code. When I go to pending codes after memory the scanner says it cannot communicate and to check key is on which it is. Now also after clearing code in both memory and pending if there. I can drive truck and seems to be fine all readings fine showing on scanner. Put truck in park and check codes and it is back in memory code. Or if I clear it not run it and turn truck off and after while turn back on eng. off code is back in memory code. Even tried disconnecting batteries for 30 min for the keep alive memory. Anyone out there with any ideas. I have been a heavy duty diesel tech for over 20 years and have not felt with small trucks so I am rattling my brain. My next step was to run new map wire harness but feel that may be just a waste of time. Also why would the scanner cause truck to not communicate after checking memory codes. It will work once I turn key off then back on
 

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Also if I try to start right after I go into memory codes it will crank but not turn over until I key off then back on
 

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So does the truck run well, or is there a problem? If it's just the MAP code and the Check Engine light is not on, I'd suggest just ignoring it. That code doesn't set the Check Engine Light till the second drive cycle.
Here are the causes of the P0236 code.
damaged MAP hose
low turbo boost
intake manifold or crossover tube hose leaks
damaged MAP sensor
damaged PCM

Did you verify you actually have adequate turbo boost? It is possible that you have up-pipe leaks or other things that may cause the turbo not to perform properly.

The fact that you get the code back without running the engine suggests it's an electrical issue. When you checked continuity between MAP and PCM, did you have someonen wiggle the harness? Maybe there's an intermittent open in the wiring.

Good luck in tracking it down. As I said at the start, I might just ignore it if everything else is OK.
 

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Is the truck tuned? If you are tuned, you can easily get over 17 PSI which will throw the code.

What is the MAP reading with the key on? Also what is the MAP reading while driving? Are you seeing MAP readings that are consistent with Boost readings?

P0236 – Fault sets if Manifold Absolute Pressure (MAP) signal is higher than the specified pressure. (MAP > 70 kPa, Manifold Gauge Pressure (MGP) > 30 kPa)
 

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All readings are correct. 14.3 at idle floor it and goes up to 23. Bone stock truck. Only thing changed is running straight pipe from last owner. Who claims light started going on after muffler was removed. But again the code shows up not even running the truck down road after I clear it and try koeo after a few min. Code is right back on memory codes
 

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Wiggles when ohm checked and cannot ignore it even though it runs great. Have to smog it as I am in calif. and both monitored have to be working. Drive it to work this morn. Cleared the code just hooked scanner back up at lunch and code and ses light is back on but it took a few seconds for light to come on and heard a click from behind radio is the a relay behind it that has to do with obd2 when connecting
 

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Sorry all but when I go to pending codes I here the click and truck turns over but will not start unless I key off then on
 

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All readings are correct. 14.3 at idle floor it and goes up to 23. Bone stock truck. Only thing changed is running straight pipe from last owner. Who claims light started going on after muffler was removed. But again the code shows up not even running the truck down road after I clear it and try koeo after a few min. Code is right back on memory codes
If that's MAP (manifold absolute pressure), then something is wrong. 14.3 would be PSIA, and 23 would be PSIG. But a stock truck should limit out at 17-18 psig. Not sure how much a straight pipe would increase boost. If the PCM has been changed out, it may have been flashed with a different program than stock.
Too bad about being in California. :|
If it's an overboost, maybe a boost fooler (pressure relief valve on the MAP sensor line) would eliminate the code. But I thought you said it would come back when you turned the key on but didn't run the engine. A boost fooler wouldn't help in that case.
 

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It only reaches 23 on the map when I floor it regular driving it is 17-18. Just would like to know now why when trying to go to pending codes I get the click and then will not communicate with any of the snap on scanners until I key off then on
 
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