At our wits end this will be the 5th MAP sensor we have put in and it will not run right. We put in a new ECM there was a error there to but that one cleared up. Now it will run if you unplug the sensor but the second it clicks into place it dies. the only code it shows now it the Po107. not sure where else to go. It is getting the right readings as in voltage in out and all that. I can unplug it and drive all over the place at least at slow speeds have not tried faster ones. Any help would be a god send. Thank you

 

Is this a 4 or 6 cylinder?

The MAP sensor is the PCM’s primary input to determine injector pulse width and spark advance based on engine load and barometric pressure. With the sensor unplugged, the PCM is defaulting to what is essentially open loop operation.

The P0107 is most likely setting because you’re running with it unplugged.

What voltages are you getting and are they key on engine off or engine running?

 

I had to rebuild the injector harness after it fell on the exhaust manifold on my 03 DGC 3.8L 4-5 yrs ago and it wouldn't run til I put a new MAP sensor on it.
If memory serves, the wiring for the MAP sensor ran through the same loom as the injector wiring.
You might make sure there's no damage to the loom by the plastic retainers getting brittle and letting the loom sag too close to the rear exhaust manifold.
I'd also make sure the loom won't drop onto the exhaust manifold. Wire ties are great for that.

Hope that helps.

 

It is a 6. When we changed the ecm and map sensor it started and ran great till we turned it off. then it threw the 107 code and would not start but for a second or two then die. I will rerun the voltage tests but they were all fine last time. we even did the test with it out and adding vacuum to the end was fine. If I plug the sensor in it will not run so cannot check those voltages. I will root around and see if all the wires are good. Would a Catalytic converter affect the sensor at all?
Thanks for the help everyone this is too nice of a van to send to scrap.

 

Could it be the brand of MAP sensor been getting Auto Zone and NAPA sensors and one off Ebay?

 

Before we get much further into this, please provide a few more details. This info is unlikely to make a difference in diagnosis but it’s possible there were manufacturing issues that are related to the problem you’re having and I can only find that out by knowing the build. If it’s in your signature or something, I’m on the mobile site and can’t see it.

1) Is it a caravan or grand caravan?
2) Is it a 3.3 or a 3.8?
3) How many miles?
4) Just out of curiosity, why did the PCM get replaced?

It’s possible the aftermarket sensors are causing the issue, but it seems highly unlikely that 5 different sensors, aftermarket or not, would be the source of the fault. I could be wrong here, but from a legal standpoint, I don’t think the manufacturer or the parts house could even sell it as a replacement part unless it meets the specifications that Dodge requires. Also, it’s not at all uncommon for aftermarket companies to manufacture OEM parts. Bosch, SMP, Delphi, Champion, NGK and others have all been OEM suppliers, past and present.

As for the converter affecting the sensor - if the converter were in bad enough condition to affect the MAP sensor readings, the engine would be running rough and misfiring with or without the sensor plugged in. An engine is basically a big air pump - air goes in and air goes out - if the exhaust is restricted enough to keep air from going out, it backs up the system and air can’t get in. The end result is bad compression and improper air/fuel ratios. A restricted converter is diagnosed fairly easily by first checking the vacuum reading at idle with the engine up to temp - if the needle is steady and holding 18-22” in of vacuum, no restriction is indicated. If it’s reading 18-22” but fluctuating more than 3” then a restriction could be the problem, but then you’ll have to either remove the upstream O2 sensor or drill a hole ahead of the converter and read back pressure in the exhaust. Anything more than 1-2 PSI of back pressure is considered a restriction.