P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input



Any thoughts on what this could be? The car runs just like it should... See mods in sig.

 

Boost spike too high? How's the BOV adjusted?

 

No irregular boost spikes, and the BOV isn't "adjusted." It's the HKS SSQV (this one doesn't require adjusting), and it's just on there, & has been for over 1 year & no problems. I don't know..... I'm thinking it might be my GMS1 MAP sensor wiring?

 

Could be if they used the crummy crimps, I soldered, heat shrinked & taped mine into the looms.

 

He got his done at the stearlership.

DTC P0108

CIRCUIT DESCRIPTION
The manifold absolute pressure (MAP) sensor that resides in the engine intake manifold is integrated with the intake air temperature (IAT) sensor 2. The purpose of this integrated sensor is to measure the following:


•The atmospheric pressure and the vacuum or the reduced pressure that exists under different operating conditions in the engine intake manifold
•The supercharged air pressure that exists under high load or wide open throttle conditions in the engine intake manifold
•The IAT 2 after the supercharger and the intercooler as it enters the engine intake manifold
•The IAT 2 after the supercharger bypass valve and the intercooler as it enters the engine intake manifold
The MAP/IAT sensor 2 has the following types of circuits:


•A powertrain control module (PCM) supplied and regulated MAP 5-volt reference circuit
•A PCM supplied ground for the low reference circuit that is shared by the MAP and the IAT sensor 2
•A MAP sensor signal circuit that supplies a voltage input to the PCM
•A PCM supplied 5-volt , IAT signal circuit
The diaphragm within the MAP sensor responds to all of the various pressure changes in the intake manifold, and provides a signal voltage to the PCM on the signal circuit, relative to those pressure changes.

The PCM monitors the MAP sensor signal for voltage that is outside of the normal range of a properly operating sensor. If the PCM detects a MAP sensor signal voltage that is excessively high, DTC P0108 sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

CONDITIONS FOR RUNNING THE DTC


•DTCs P0120, P0121, P0220, P2135 are not set.
•The engine has been running for a calibrated length of time, that is determined by the start-up engine coolant temperature (ECT). The length of time ranges from 2 minutes at less than -30°C (-22°F) to 1 second at more than 30°C (86°F) .
•The TP Indicated Angle parameter is less than 90 percent , when the engine speed is less than 1,000 RPM .OR
•The TP Indicated Angle parameter is less than 98 percent , when the engine speed is more than 1,000 RPM .
•DTC P0108 runs continuously when the above conditions are met.
CONDITIONS FOR SETTING THE DTC
The PCM detects that the MAP sensor signal voltage is more than 4.90 volts for more than 2 seconds .

ACTION TAKEN WHEN THE DTC SETS


•The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
•The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC


•The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
•A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
•A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
•Clear the MIL and the DTC with a scan tool.
TEST DESCRIPTION



Steps 1 - 11

Steps 12 - 14
The number below refers to the step number on the diagnostic table.


2.The MAP sensor 5-volt reference circuit is shared with other sensors. If DTC P0651 is set, this indicates a shorted 5-volt reference circuit, or a shorted component, and should be diagnosed first.

if you want the steps i can email them to you.