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Ask Dodgerench Your Own Question
Dodgerench, ASE Certified Technician
Category: Dodge
Satisfied Customers: 3404
Experience:  30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
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My name is leon on my truck 1500 dodge ram with a 5.7 I have

Customer Question

hi my name is leon on my truck 1500 dodge ram with a 5.7 I have a code saying barometric pressure too low what can I do to fix it please
Submitted: 1 year ago.
Category: Dodge
Expert:  Dodgerench replied 1 year ago.

Hi, welcome to JustAnswer!. This is Ed.

You almost certainly need a new Manifold Absolute Pressure (MAP) sensor. A P0129 BAROMETRIC PRESSURE OUT OF RANGE LOW trouble code tells me that the PCM (engine controller) had seen a reading from your MAP sensor during engine start that was too low for it to have been a realistic barometric pressure reading, yet too high to have been a simple electrical fault. This code may be set in error if you were to rev the engine to a high RPM, shut the key off, then turn it back on before intake vacuum had a chance to equalize with atmospheric pressure, but you'd have to try to do that. Unless there was a circumstance when you know of the key being cycled back on with the engine still spinning, I would recommend MAP sensor replacement.

Locations for MAP sensors on the 5.7 engine vary slightly, but will always be on the top of the intake manifold. In the case of a 2006 Ram with the 5.7 liter, you'll find it between the alternator and A/C compressor (to the rear). The sensor requires removal of the connector first, as it "unscrews" by turning it a quarter turn to the left, then lift. The connector interferes with a vertical stop that prevents the MAP sensor from coming out on its own. Install the new sensor, perform a 2-minute batter disconnect to clear your P0129 trouble code and you should be all good.