Dear friends,

I've been trying to diagnose the source of the dreaded P0106 (H) code. I have tested the engine vacuum lines using a smoke tester hooked up to the PCV return connecting to the air intake. I don't have any vacuum leaks based on the smoke test. I've also pulled the intake manifold, inspected the seal of the MAP sensor (original sensor) cleaned and reinstalled it. I've also cleaned the throttle body for good measure. The wiring & connector to MAP sensor appears to be intact. I am losing my mind trying to figure out what could be causing this issue.

The error code P0106 pops up after a long drive approximately 90 miles after clearing it every time. This is repeatable. The MAP sensor appears to be responding to air flow changes when Tech2 is connected and data is being read from the engine. The car drives perfectly otherwise and there are no other DTC codes. Attaching some Tech2 screenshots of the P0106 freeze frame captured from last event.














Vehicle Specs
2004 Corvette Base
103,000 Miles
Original MAP Sensor (checked cleaned and reinstalled it)
A&A Super Charger, Vortech v3 Intercooler, Air Intake
A&A Tune
Original Headers (Car was tuned with Doug Headers, removed them and replaced with original due to steering column rub)
High Flow Fuel Injectors


Any advice would be appreciated.

God Bless,

Mike

 

HOW did you check your MAP sensor ??...I used my Tech 2 and this is what I see at 2000 RPM below..a dirty throttle body can set a P0106 but you said you cleaned it...the DTC must have set when you let your foot off the gas because your APP Indicated angle is 0%...the PCM looks at throttle position and RPM to calculate predicted MAP value... the PCM knows this value by voltage and not pressure…if the voltage is wrong (high resistance in the wiring it will report a bad number)…now you said "the wiring and connector APPEARS to be intact"...that's not good enough !!...if you want to check it with a DVOM I can run you through that if you want to get back there again...there are 3 wires...a 5 volt ref, a signal, and a low reference (ground)...you can check the signal wire by jumping the 5 volt ref. to that signal wire...the Tech 2 MAP voltage will read 5 volts if the signal wire is good...you should see 5 volts on the ref wire, less than 100 mv's on the ground and that good signal wire back to the PCM...if wiring is OK I'd change the MAP sensor.

Key On Engine Off - 101 kPa ---based on my car at sea level

2000 RPM:
MAP Sensor- 25 kPa
MAP Sensor- .79 volts
Baro- 100 kPa
TP Desired and Indicated- 12%

 

Can a "bad" MAF (not MAP) sensor also be the cause for the P0106? Ocassionaly i have idle hesitation where the car wants to die when you turn off AC at idle for example.

Here are my readings @2000RPM

MAP Sensor 25Kpa
MAP Sensor 0.82 volts
BARO 103Kpa

 

Since you have a Tech2 I recommend you to connect it to your car and setup the SnapShot options to start recording when DTC P0106 appear.
Next time you get P0106 the Tech2 will record a lot of PID's and hopefully " the bad guy PID " will appear when you review the SnapShot

You Tube

 

Thank you very much. Good suggestion. I will attempt this as well.

 

I don’t think it can (MAF) and the only thing is we don’t know the PCM strategy for these DTC’s since that’s not published !!…usually stalling like that is a dirty throttle body and as long as your TP angle is below 10 you should be OK…my suggestion is to check the circuit with a DVOM and if it looks good change the MAP sensor…if you have something like a Mityvac you can check the MAP sensor by applying vacuum and then check the reading but it’s just easier to change it !!

 

All,

I wanted to provide some additional interesting data points for any future owners who might experience this issue.

In my case the the P0106 would pop up exactly at 90 miles every time. This happens every time I clear the ECU of all codes or disconnect the battery for a long time. I believe that this condition is related to the ECU relearn, SMOG/EVAP procedure which the computer has to go through every time you reset it. So this time around, i did NOT reset my codes, the check engine MIL light goes away after every two successful cold start cycles where the MAF check passes. So the MIL light is gone but the P0106 is in history. What is interesting that after driving another 100+ miles, the MIL light did not come on. I also had the Tech2 scanner hooked up ready to take a snapshot but since the code was not triggered, no snapshot was created.

Here is where i am now.

• Brand New MAP Sensor
• All vacuum lines checked and accounted for: No vacuum leaks
• MAP Sensor connection checked: Clean & in great connection. Nothing lose, nothing broken nothing corroded.
• MAP Sensor 5V reference checked with DVOM, looks great.
• Vehicle drives great with no other codes or indications of issues.

SMOG Cylcle NOT completed:
Catalyst | Not Ready
EVAP | Not Ready
AIR | Completed
Oxygen Sensors | Completed

 

I had a similar situation, if your car is boosted your MAP sensor maybe giving out very soon, To my understanding, If you are a 1 Bar there is a small strap inside that Map that stretches and measures vacuum and a maximum pressure at 14.6 psi, if your close to this boost wise, its possible you over stretched this strap and not reading correctly.

My car is also boosted and left me stranded when mine MAP snapped, My car was tuned going off the MAF, and it also failed me.