2001 cummins code P0237

[gregjo1948]

Dodge runs fine at idle. Throttles up to higher rpm very slowly. Has no power.
Code reads; Manifold absolute pressure sensor
Low voltage

I installed a new MAP sensor and got no change in performance.
I'm looking for suggestions.
Thanks, gregjo1948

 

[dapepper9]

Do you have a boost leak?

 

[gregjo1948]

Do you have a boost leak?

How do I find a boost leak?
Thanks, gregjo1948

 

[dudeman2009]

How do I find a boost leak?
Thanks, gregjo1948

One option is to listen for a hissing noise when you hit the throttle.

Another is to spray soap water on the joints of the tubes after the turbo.

 

[gregjo1948]

This is a cummins....it's noisy! LOL I'll listen but, I think the soapy water will be better.
The code said MAP low voltage. What does that mean? Thanks, gregjo1948

 

[jlbayes]

Doubt it is a boost leak with that fault.

https://mopar1973man.com/cummins/ar...odes_94/p0237-map-sensor-voltage-too-low-r65/

 

[MADDOG]

What it means is the PCM sends a 5 volt reference signal to the MAP sensor and the MAP sensor sends a variable voltage signal back to the PCM. When boost pressure is high the voltage signal is high. When boost pressure is low the voltage is low. The PCM uses the boost control solenoid to control the amount of boost pressure that is produce by the turbocharger while at the same time using the boost pressure sensor to verify that the boost pressure is correct.

Potential causes for this code to set are:

Boost pressure leak
Faulty boost sensor "A"
Faulty turbocharger
Faulty PCM Wiring problem

I'd work my way through the potential failures in this order:

1. Make sure there are no other codes present.
2. Check for boost pressure leaks.
3. Check all wiring and connections to the boost sensor. Make sure the o-ring is on the sensor and check all harness connections for frayed wires, cracked connectors and clean them.
4. Replace the boost sensor.
5. Pull and inspect the turbo.

Also, this video may be helpful:

https://www.youtube.com/watch?v=g_7LgtckNrc

 

[gregjo1948]

If I have low boost, will that disturb the manifold pressure, causing the MAP sensor to emit a low voltage code?

 

[MADDOG]

I doubt it. A low voltage code indicates a faulty connection, a wire to ground or a failed sensor.

 

[gregjo1948]

I built a gobwhobbie, so I could check my boost for leaks and found a faulty gasket between the intake manifold and the intake air heater. Fixed that problem but, it didn't solve my main problem. I went back to try to find a wiring fault and I found that the Quadzilla that the previous owner had added was the culprit. Removed it and the truck runs great again. Thank you for your help. gregjo1948