2.3L ('02-'11) Check engine light question

[TrevWard]

I have a check engine light on. I took my 2010 Ranger ( XL/XLT Supercab 2.3L) to AutoZone to run a diagnostic on the check engine light.

Here is the result:
PO108 Manifold Absolute Pressure (MAP) BARO Sensor High Input
PO453 Evaporative Emission System Pressure Sensor/Switch High Input
PO643 Sensor Reference Voltage A Circuit High.

Has anybody had similar issues, if so, what is the fix?

Thanks,

 

[RonD]

Welcome to TRS

First one to deal with is P0643, this is a PCM(computer) issue, so other 2 codes may not be "real" or are caused by this fault in the PCM

One possibility is a shorted sensor or sensor wire

The PCM has a 5volt output voltage that is SHARED with most engine sensors, P0643 could be this 5volt wire is shorted some where so voltage is low

Easiest place to test this 5 volts is at the TPS(throttle sensor)
Unplug its 3 wire connector
Turn key on, engine OFF
Test all 3 wires for 5volts using engine as ground

Its usually the top wire but................green/white or green/purple wire

If there is no 5volts then unplug MAP sensors(P0108) 3 wire connector and see if voltage returns or comes up

 

[TrevWard]

Thanks for the thorough and quick reply.