02 GC 4.7L V8. KEY ON< or RUNNING?
we cant guess that.
why not post the symptoms, so we can REALLY HELP YOU.
GOT DTC's what are they,. scan it yet, if not?, why not scan it.?
my guess is you are working FSM free? none.?
MAP. (manifold air pressure or BARO) top front of intake plenum man.
2 fuses drawing,
what does that mean?
all fuses draw current.
why not post symptoms, ???????????
the fsm shows the MAP readings and vacuum and voltage output
chart, the MAP is BARO SENSOR, CALLED A 1 BAR BARO.
in simple terms it measures plenum vacuum and the PCM injects
based on that and on IAT plenum air temperatures.
with 2 sensors this engine measure AIR flow through the system.
the PCM creates 5vdc called 5vREF. The PCM has a regulator inside
the PCM to creates 5v, for the 4 external sensors.
TPS, MAP, Crank and Cam sensors. all run off 5vdc power.
YOUR map has 3 pins,
1 blk /Lb is ground from PCM. (black, light blue?)
2- output color DG/RD (darkgreen-red) bingo, sensor output.
3- orange, 5vdc all time key on.
weather and altitude changes MAP readings. ask for the rules.
Baro means barometer.
its and electronic barometer. or Baro for short.
here is cheat sheet (HG is standard mechanics, vacuum tool called relative vacuum )
The voltage is inversely proportional to Vacuum. (relative)
HG " volts. (DMM backprobing conn.)
0 = 4.8v
5 = 3.9v
10 = 3.1v
15 = 2.1v
20 = 1.1v
28"HG = 0.5 (radical deceleration, in gear, throttle cut, down hill)
do not use my numbers as verbatim, get your own FSM
and see the chart for your sensor on your engine.
keep in mind the ECU provides the ground to this sensor.
so measure ground on the sensor to the battery, minus.
should be less than 0.5vdc.
then measure 5v, on the 5vdc pin, yes, good.
this is the correct order, sensors can not run, with bad power.
does engine run?
dose enigine pull (hand gauge) 20"HG it idle, if way lower, there can
be burned intake valves.. if the vacuum pulsed badly that too
is bad valves. the ECU can not run a bad engine., not that bad.
The ecu can only compensate for normal wear, not dead cylinders.