Getting a PCM P0101 after CAI installation

[Sergey21]

Well, the title says it all, do I need to re-calibrate my PCM, or what?

[Ranger]

You need to get rid of that CAI. I was going to tell you that it was going to cause you problems, but you probably wouldn't have believed me anyway. Figured I'd let you find out for yourself. Do a search for CAI and read up on it. You're not the first. If you checked out your original intake system, you'd see that it is already CAI. The air intake is behind the headlight drawing in cold air which also cools the PCM as air is drawn over it.

[Sergey21]

Anyway to bypass that sensor? I mean why would it be doing that, can you explain in about 2 - 3 sentences for me to get a better understanding on the issue?

[Ranger]

Bypass it and you create even more problems. Go back to the OEM system. You are not gaining anything with this thing. Go do a search and see what I mean.

[Sergey21]

Ranger, but I've got proof of it working! When I had my old intake system I was getting 17.4mpg now I get 18.6. My RPM's go up higher, and my idle is lower. Throttle is more responsive and a lot more touchy.

So theres no way to bypass it then huh. Damn! Ima take it to get the PCM recalibrated at my buddies shop.

[submariner409]

Sergey, Before you take the PCM to a shop, do us a weekend favor: You feel that your air intake has done a couple of wondrous things for your engine. Spend the half hour and return the intake to the stock setup, using a new panel filter, your choice. Sure, PITA, but it now gives you baseline. After a few honest days of comparison, go back to your aftermarket setup and do another honest judgement. Post your findings.

[Sergey21]

I will take your advice.

Also, this PCM P0101 comes and goes whenever it pleases, I also think that it is doing this because I sprayed WD-40 on the sensor, in order to stick it in through the rubber hole on the intake. Been a day, and the code hasn't came up.

[CadillacSTS2003]

1st i will answer what i think
i think your basing this by a seat of the pants dyno rather than an actual improvement

driving habbits alone major depend on weither or not you will have an MPG increase, Corsa guarantees and increase that because of my heavy foot I havent and will probably never see....

2nd i will post all you want to know about P0101
Document ID# 237042
1998 Cadillac DeVille
DTC P0101 Mass Air Flow (MAF) Sensor Performance

Object Number: 244383 Size: SF
Click here for detailed picture of above image.
Circuit Description

This diagnostic test is used to determine if the Mass Air Flow sensor is providing proper readings to the PCM. The MAF sensor is a high frequency device that measures the rate of air flow through the throttle body. The MAF sensor outputs a series of pulses that vary in frequency with air flow. This signal is used by the PCM for fuel control. MAF readings during acceleration will be much higher than those during deceleration or idle. The PCM calculates what MAF reading should be received from the sensor under certain conditions. When the test conditions are met, the PCM will compare its calculated MAF value to the actual value received from the sensor. The calculated MAF reading is done by comparing MAP, RPM and Intake Air Temperature. The allowable difference between calculated MAF and actual MAF varies depending upon flow. If this difference is too great DTC P0101 will set.
Conditions for Running the DTC

* DTCs P0102, P0103, P0106, P0107, P0108, P0121, P0122, P0123, P0560 and P1108 not set.
* Ignition voltage between 11 volts and 16 volts
* DTC P0101 has not previously failed this ignition cycle.
* In closed loop fuel control.
* Canister Purge Duty Cycle is less than or equal to 99.6%.
* EGR rescaled pintle position is less than or equal to 240 counts.
* DTC P0401 not testing EGR.
* Traction control not active.
* TPS is less than or equal to 50 degrees.
* 100 msec delta MAP is less than or equal to 5 kPa.

Conditions for Setting the DTC

The difference between the actual and calculated MAF has been too great.
Action Taken When the DTC Sets

* PCM disables the EVAP control solenoid.
* PCM disables long term fuel trim.
* PCM substitutes calculated MAF value, based on engine speed and throttle position, for actual MAF.
* PCM disables torque management.
* PCM maintains transaxle shift adapts at their current levels.
* PCM disables TCC.

* The PCM will illuminate the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
* The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

* The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
* A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
* A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
* Use a scan tool to clear DTCs.
* Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Diagnostic Aids

For an intermittently setting DTC P0101, compare the Freeze Frame data to the Typical Data list for the conditions under which the DTC set, looking for faulty data from other sensors which may set this DTC.

Important

An improperly installed air cleaner or a distorted /missing Intake Air Duct may cause this DTC to set. Ensure air cleaner assembly / IA duct is installed correctly and that there are no kinks, folds or damage to the IA Duct or possible debris in the air cleaner assembly or the MAF sensor inlet screen that may distort the air flow.
Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2.

Since calculated MAF is based on many inputs, these DTC's should be diagnosed first. If a miss or a rough running complaint is noted with or without DTC P0300, proceed to P0300 diagnosis first.
3.

Leaks downstream of the MAF sensor affect engine performance and actual MAF but won't be reflected in the calculated MAF sensor reading and may cause DTC P0101 to set.

Step


Action


Value(s)


Yes


No

1


Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?


--


Go to Step 2


Go to Powertrain On Board Diagnostic (OBD) System Check

2


Connect the scan tool.

Are DTCs P0106, P0107, P0108, P0112, P0113, P0300 , P0401, P0441, P1106, P1107, P01108, P1404, P1406, P1441, P1442, P01508, P01509 or P1645 also set?


--


Diagnose those DTCs first


Go to Step 3

3


1. Check for vacuum leaks especially in the following areas:
* MAF Sensor seal.
* Throttle body spacer.
* Intake manifold.
* EGR valve, plate and tubes.
* PCV system.
* Brake booster and hoses.
2. Repair leaks if needed.

Was a vacuum leak repaired?


--


Go to Powertrain Control Module Diagnosis for Verify Repair


Go to Step 4

4


1. Check for the following:
* A stuck or incorrect PCV valve.
* Unmetered air entering the engine (loose or missing oil dipstick or filler cap, loose or missing Intake Air duct.
2. Repair or replace as needed.

Was a repair made?


--


Go to Powertrain Control Module Diagnosis for Verify Repair


Go to Step 5

5


Using Freeze Frame and Failure Records data, duplicate conditions under which DTC P0101 set.

Does DTC P0101 reset?


--


Go to Step 6


Fault not present. Refer to Diagnostic Aids.

6


Refer to DTC P0106 Manifold Absolute Pressure (MAP) System Performance and perform the diagnostic table. Return to this Step.

Was a repair made to the MAP sensor?


--


Go to Powertrain Control Module Diagnosis for Verify Repair


Go to Step 7

7


Replace MAF sensor. Refer to Mass Air Flow (MAF) Sensor Replacement .

Is the replacement complete?


--


Go to Powertrain Control Module Diagnosis for Verify Repair


--


3rd there is NO ONE that can "program" your pcm to not have a maf... AJ can do somethings but i dont think he has come that far yet, but im sure your average shop can do NOTHING.

[91parkave]

or you could reset the PCM codes via the DIC method. It happened to 2 cadillacs i installed custom CAI's on, reset the computer no more check engine light after 10,000+miles

[CadillacSTS2003]

reseting it JUST clears the code THAT time
it doesnt erase the PCMs hard memory where it wants to recognize a MAF sensor....

[91parkave]

say what you want but i had no check engine light after ressetting the codes.

[CadillacSTS2003]

i mean no argument
but i dont see how its possible to reset logic in the pcm by clearing a code twice

[Ranger]

Sergey, Sergey, Sergey, don't mess with the PCM! You're gonna be back with MORE problems. Get some electronic parts cleaner or Brakleen and spray the MAF sensor if you got any WD40 on it. You are not accomplishing anything with that CAI, except in your own mind. The air filtration system was designed to allow the Northstar to breath all the air that it can take at redline with WOT. The OEM filter is NOT restrictive.

[CadillacSTS2003]

oh it is restrictive Ranger
just not for a N* haha

[submariner409]

If anyone wants to put this dead horse idea to bed forever, tap a 0" -30" vacuum gauge into a T fitting spliced into one of the nipples on the intake manifold side of the throttlebody. Stick the gauge to the windshield wiper area in front of the driver's side windshield, using some non-hardening putty (monkey shit). Do several D range full throttle runs to around 80 mph. Change your air intake back to what it was.....stockish or so-called CAI. More WOT runs. If the WOT Acceleration vacuum readings are within an inch or two of 0", you have accomplished nothing. Nothing. The atmosphere can only push so much air into an open vacuum volume depending on restrictions in the inlet. (The engine doesn't "suck" it in: air rushes in to fill a vacuum, and a shut butterfly = maximim manifold vacuum, a wide open butterfly = minimum manifold vacuum.) Naturo abhorret a vacuuo. You wanna get the best gas mileage??? Drive for maximum vacuum. (For you "cold air" guys, don't forget that the throttlebody is coolant heated (yes, below WOT) to 206 degrees to prevent icing in the intake passages.......forgot about that, huh ???)