P102 Code - 2001 with 83000 miles

[cagashe]

I have 2001 LeSabre with 83000 miles on it.

The car was dying earlier intermittently at low speeds. The problem for car dying turned out to be bad fuel pressure regulator. I fixed the same with a $60 replacement part.
I always have had this fuel gauge dancing low to high and my mechanic suggested it will need entire fuel pump and other related parts to be replaced (appx $500+).
He advised I better keep an eye on the gas filled in vs miles I am driving and reset the odometer (trip reset) every time I fill the gas. With this the car was running great until last week.

Last week for some reason, I believe I ran out of gas and the car died. I filled the gas again and started the car with no luck. I then waited for about 30 minutes and started again. The car started shaking at first but then eventually started with "Service Engine Soon". I rushed to Orilley to scan the code and it was P102. I cleared the code and drove for 30 miles. Well the "SES" came back again with same code.

I also noticed that now if I keep the car idle for more than a day and then start again its little shaky for 10 seconds and I have to push gas paddle hard for first time.. then everything runs normal.

My initial guess was its just a sensor issue and would get resolved automatically, but shaking car is weird. I DO NOT want to spend on fixing something that "may seems" to be an issue. Any inputs/DIYs will be of great help.

 

[lkraemer]

A quick search at http://www.dtcsearch.com for code P0102 shows a
possible MAF problem.

How would you test a Mass Air Flow (MAF) Sensor?
http://www.buickforums.com/forums/showthread.php?t=24413&highlight=Mass+Air+Flow&page=3
Posting #21

Larry

 

[Enslow]

First try unplugging the MAF sensor connector and see if the symptoms go away. If it still dies, your first problem is not the MAF. The P0102 can be set because the MAF is faulty, OR something is causing the MAF to send a low signal to the computer. Here's a useful link:

http://www.chevyavalanchefanclub.com/cafcna/index.php?topic=22615.0;wap2

If you have a scantool, you can observe the MAF signal while your problem occurs, then see if you can find out what is causing the MAF to read low. If nothing appears to cause the MAF to read low, and the wiring for the MAF is OK, it's time for a new MAF.

I ended up having two problems. I had a bad MAF, and I had a bad IAC. A junkyard IAC worked fine, but I paid for a new ACDelco MAF.

 

[Merkava_4]

Here's the description of P0102:

CIRCUIT DESCRIPTION

The Mass Air Flow (MAF) sensor measures the amount of air which passes through it into the engine during a given time. The PCM uses the mass air flow information in order to monitor the engine operating conditions for fuel delivery calculations. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle. The MAF sensor produces a frequency signal which can be monitored using a scan tool. The frequency will vary within a range of approximately 2000 Hertz at idle to approximately 10,000 Hertz at maximum engine load. DTC P0102 will be set if the signal frequency from the MAF sensor is lower than the possible range of a normally operating MAF sensor.


CONDITIONS FOR RUNNING THE DTC

The engine is running.

TP angle is less than 50% .

System voltage is more than 9 volts .

CONDITIONS FOR SETTING THE DTC

The MAF signal frequency is less than 1200 Hertz .

The above conditions are present for longer than 0.5 seconds + 400 3X reference periods, or 133 crankshaft revolutions.

ACTION TAKEN WHEN THE DTC SETS

The PCM will illuminate the Malfunction Indicator Lamp (MIL) the first time the malfunction is detected.

The PCM calculates an airflow value based on the idle air control valve position, the throttle position, the RPM and the barometric pressure.

The PCM will store the conditions which were present when the DTC set as Freeze Frame and the Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC

The PCM will turn the MIL OFF during the third consecutive trip in which the diagnostic has been run and passed.

The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS

Check for the following conditions:

A poor connection at the PCM. Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connections. Use a corresponding mating terminal in order to check for proper terminal tension.

A misrouted harness. Inspect the MAF sensor harness to ensure that it is not routed too close to high voltage wires such as spark plug leads.

A damaged harness. Inspect the wiring harness for damage.
If the harness appears to be OK, observe the scan tool while moving the connectors and the wiring harnesses related to the MAF sensor. A change in the display will indicate the location of the malfunction.

Plugged intake air duct or filter element. A wide-open throttle acceleration from a stop should cause the Mass Air Flow displayed on a scan tool to increase from approximately 4-7 gm/s at idle to 100 gm/s or more at the time of the 1-2 shift. If this does not occur, check for a restriction.

If DTC P0102 cannot be duplicated, the information included in the Fail Records data can be useful in determining vehicle mileage since the DTC was last set. This may assist in diagnosing the condition.

 

[cagashe]

Thanks guys,

In order to get this repaired/tested by a mechanic, what is the $$ I should be looking at? I stay in Northwest suburbs of Chicago.

 

[redmondjp]

Thanks guys,

In order to get this repaired/tested by a mechanic, what is the $$ I should be looking at? I stay in Northwest suburbs of Chicago.

You're likely to pay anywhere from $100-150 for a basic diagnosis. If you can find a good, independent mechanic/driveability specialist that knows GM products well, that would be best.