How to replace the over head map lights or the center over head reading lights

Under hood, center, rear engine area, above valve cover, mounted in bracket.

From autozone.com:

Manifold Air Pressure Sensor

Fig. MAP sensor specifications-note how altitude and pressure affect the voltage readings
REMOVAL & INSTALLATION

1. Remove the intake manifold top cover.
2. Disconnect the crankcase breather tube from the throttle body.
3. Remove the MAP sensor from the intake manifold.
4. Detach the MAP sensor electrical connector.
5. Inspect the MAP sensor grommet for wear or damage and replace as needed.

To install:

1. Installation is the reversal of the removal procedure.

Hi there:
DTC P0108 - Manifold Absolute Pressure/BARO Sensor High Input




Check the potential causes of a P0108 code:

Bad MAP sensor
Leak in vacuum supply line to MAP sensor
Engine vacuum leak
Short on signal wire to PCM
Short on reference voltage wire from PCM
Open in ground circuit to MAP
Worn engine causing low vacuum


Now, about the possible solutions... a good way to diagnose if the MAP sensor is to blame would be to compare the KOEO (key on engine off) MAP sensor reading on a scan tool with the Barometric pressure reading. They should be the same because they both measure atmospheric pressure.

If the MAP reading is greater than 0.5 volt off of the BARO reading, then replacing the MAP sensor would likely fix the problem. Otherwise, start the engine and observe the MAP reading at idle. It should normally be about 1.5 volts (varies according to altitude).

a. If it is, the problem is likely intermittent. Check all the vacuum hoses for damage and replace as necessary. You can also try wiggle testing the harness and connector to reproduce the problem.
b. If the scan tool MAP reading is more than 4.5 volts, check the actual engine vacuum reading with the engine running. If it is less than 15 or 16 in. Hg, then the PCM is probably not seeing enough vacuum (due to a worn engine, perhaps) for a given operating condition (which causes a higher than normal voltage signal to the PCM) and setting the code. Repair the engine vacuum problem and retest.
c. But, if the actual engine vacuum reading is 16 in. Hg or more, then unplug the MAP sensor. The scan tool MAP reading should indicate that there is no voltage present. Check that the ground from the PCM is intact and also that the MAP sensor connector and terminals are tight. If the connection is good, then replace the map sensor.
d. However if, with KOEO, & the MAP sensor unplugged, the scan tool shows a voltage reading, then there may be a short in the harness to the MAP sensor. Turn the ignition off. At the PCM unplug connector and remove the MAP signal wire from the connector. Re-attach the PCM connector and see if with KOEO, the scan tool MAP reading shows voltage. If it still does, replace the PCM. If not, check for voltage on the signal wire you just removed from the PCM. If there is voltage on the signal wire, find the short in the harness and repair.

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Hello! lets check the Manifold Absolute Pressure (MAP) and the Throttle Positioning Sensor (TPS) in that order...if you have a multimeter and a wee bit of experience using one both of these sensors can be tested...If not replace the MAP first and the TPS second...

The MAP has a three wire connector with wire colors Orange/White...Blue/Light Green...And Black./White...using two safety pins push one into the rear of the in-place connector into the Blue/Light Green...The other into the Black/White...connect the + probe of the meter set to read 5 volts on to the Blue/Light Green pin...the - probe to the Black/White pin...turn key to on...Meter must read at least 3 volts...If not MAP is defective...

Using the same technique lets test the TPS...Three wire connector Green/Light Green...Orange/White and Black/White...Safety pins into Green/Light Green and Blue/White...Set meter to read 5 volts...Place + probe of meter on Green/Light Green pin...And - probe on Black/White...start the engine...at idle meter must read less than 1 volt (.85)...slowly increase the idle (as best you can)...Meter should rise smoothly to 4 volts...If it skips, jumps or acts erratic the TPS is defective...See pictures below...Guru...saailer

MAP

TPS

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Hello! I suspect a defective Manifold Absolute Pressure (MAP) sensor...Located under hood, center, rear engine area, mounted on the upper firewall...Three pin connector...Wire colors...Brown/White...Light Green/Black...And Gray/Red...It can be tested if you have a voltmeter...Push a safety pin into the rear of the in place connector on the Light Green/Black wire...Another pin into the rear of the connector on the Gray/Red wire...Set meter to read 5 volts...Place +probe of meter on the Light Green/Black and - to Gray/Red...Turn the key to on...Should read 4 volts...If voltage is 3 volts or less the MAP is defective...This part is called "the fuel boss" and will give the symptoms the vehicle has...Cost is around $100...See picture of MAP below...Guru..Saailer



I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Hello! The PERCUS...E...Code is an Electronic Control Module (ECM) programming error or failure...The grounding may be at fault...Using an ohm meter set on X10 scale...Read from center of negative battery post to bare metal on chassis and then to engine block...Should read very near zero ohms...If these readings are OK...The ECM needs to be re-flashed (reload software) at a dealership.

MAP reading across wire colors Black/White (+) and Black/Green (-) at idle should be 1.1 volts...(.99 is a correct reading)...Throttle up and voltage increases to 3.75 volts w/o erratic movement...This indicates MAP is OK...

Guru.............Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Pop the cover off with flat-head screwdriver, then pull the bulb straight out and push new one in.

Using a scan tool, watch the MAP sensor value with the key on, engine off. Compare the BARO reading with the MAP reading. They should be roughly equal. The voltage for the MAP sensor should read approx. 4.5 volts. Now start the engine and look for a significant drop in the MAP sensor voltage indicating the MAP sensor is working.

If the MAP reading doesn't change perform the following:

With the Key on, engine off, disconnect the vacuum hose from the MAP sensor. Using a vacuum pump, pull 20 in. of vacuum on the MAP sensor. Does the voltage drop? It should. If it doesn't inspect the MAP sensor vacuum port and vacuum hose to manifold for a restriction of some kind. Repair or replace as necessary.
If there are no restrictions, and the value doesn't change with vacuum, then perform the following: with the Key on and engine off and the MAP sensor unplugged, check for 5 Volts at the reference wire to the MAP sensor connector with a Digital Voltmeter. If there is none, check for reference voltage at the PCM connector. If the reference voltage is present at the PCM connector but not the MAP connector, check for open or short in the reference wire between MAP and PCM and retest.
If reference voltage is present, then check for existing ground at the MAP sensor connector. If it isn't present then repair open/short in the ground circuit.
If ground is present, then replace MAP sensor.

2825 bulb

may have vacume leak .unpluging map sensor will set a code light.

You have to pull it down from the head liner. Start at one side or the other and you should notice a little play it simply pulls down from the head liner.