Code 41//Locate Cam Sensor

[ellev8or]

92 PA
134,000 miles

I'm constantly getting a 'Code 41' and now my fuel economy is almost 100 miles less than usual on a full tank. I've gotten some great advice from the experts here concerning the issue and was wondering what could be causing the decrease of fuel economy?

Also, can someone please direct me to the location of the cam sensor and the directions for replacing. I've tried the AutoZone site to locate it but it was difficult to decipher.

Thanks in advance!

[82Stang]

This may be of some help to you...
http://www.gmforum.com/buick-172/92-...ircuit-305206/

[ellev8or]

I've just paid $400 to replace the cam sensor interruptor magnet and cam sensor. Arrived home and cleared the codes and the 'Check Engine' light is still on. I checked it to see what codes were popping up. At first, it was code 31 and 41. Now its only 41. What else could be causing the code? The tech at the shop stated that the harmonic balancer and the water pump pulley could cause code 41. Is this so?

Thanks in advance.

[Tech II]

Wait a minute, you paid $400 for a job.....did this mechanic diagnose it as the magnet? And why did you have to clear the codes?

[ellev8or]

@ Tech II

I was told by three different auto mechanics that it was the magnet but they all charged in between $900-$1200. They all said it was major engine work. But the shop who charged $400 was certain it was something else and wanted to charge me diagnostic for three hours at a rate of $125. They did no diagnostic because I didn't allow them to but they didn't replace the timing belt while replacing the magnet. They only replaced the timing cover. Neither did they give me any info regarding the timing chain. The shop that charged $400 stated that it was the harmonic balancer and the water pump and stated that the two could cause the code 41.

In two days my fuel economy has gotten significantly worse and now the 'Check Engine' indicator stays on the entire time the car is on. What else do I need to consider for the answer to this code 41 and fuel economy?

Thanks in advance.

[Tech II]

This just keeps getting better and better......

I was told by three different auto mechanics that it was the magnet but they all charged in between $900-$1200. They all said it was major engine work.

I don't know how in the world you can say it's the magnet unless you do diagnostics on the vehicle.....

But the shop who charged $400 was certain it was something else and wanted to charge me diagnostic for three hours at a rate of $125.

Three hours to diagnose a job that should take about 1/2 hour if you have the equipment and knowhow?


They did no diagnostic because I didn't allow them to but they didn't replace the timing belt while replacing the magnet.

So you are the one at fault here....you told them to replace the magnet, without diagnostics being involved(i'm sure your typing of a timing belt was a typo).


They only replaced the timing cover.

They replaced the timing cover?

Neither did they give me any info regarding the timing chain.

While they were in there, they should have inspected the back of the timing cover, the button/spring for the camshaft, the condition of the cam and the crank sprocket, the timing chain and the tensioner, and noted it on the repair invoice.

The shop that charged $400 stated that it was the harmonic balancer and the water pump and stated that the two could cause the code 41.

Was your Water pump leaking? So they were pulling this out of the ethers, because you wouldn't give them 3 hours to diagnose? Run, don't walk....Off the top of my head, I could name several things that could cause this, but without diagnosatics to back it up, it means nothing....

In two days my fuel economy has gotten significantly worse and now the 'Check Engine' indicator stays on the entire time the car is on. What else do I need to consider for the answer to this code 41 and fuel economy?


Sure your fuel economy is in the shitter, because the injectors are not firing at the right time....

At this point you have to go to someone who KNOWS WHAT THEY ARE DOING!.....

This not hard to diagnose, with the right tools(voltmeter and scan tool, Tech I or II, and the trouble tree for code 41).......

The ECM, gets the signal from the ICM....the ICM gets the signal from the Cam sensor....just a matter of seeing where the signal problem is, but you need the tools and knowhow....it could be something as simple as a bad female connection in a harness.....just have to know where to look....

[ellev8or]

Is the computer the ECM?

Can a faulty ECM cause the code 41 if a new cam sensor and a new cam interruptor magnet has be installed?

Can slack in the timing chain cause code 41?

I had a different tech check ICM, ICM wire harness, ignition coils, spark plugs and spark plug wires and everything checked out fine. He believes its the ECM.

Thanks

[ellev8or]

I've just replaced the ECM and the 'Service Engine Soon' light is still on. I don't know what else to do at this point. Can someone please help.

[Tech II]

I had a different tech check ICM, ICM wire harness, ignition coils, spark plugs and spark plug wires and everything checked out fine. He believes its the ECM.

When you guess, you become a parts changer.....

That tech should have checked the signal into the ICM....if ok, did he receive a cam signal from the ICM? if no, then you check the wiring/connections between the ICM and ECM....if ok, you replace the ICM...

[ellev8or]

I returned to the shop that did the $400 job for replacing the cam sensor and cam interruptor magnet, because the code 41 has not been cleared. They charged me another $100 for diagnostic and stated it would take at least an hour. In less than 15 minutes they returned with the results and this is what they found: timing chain and water pump needs to be replaced for $1600.

I asked why the timing chain could not be replaced the first time as they were replacing the cam sensor and magnet, their reply was that they didn't replace the cam sensor and magnet through the timing area but through a port hole under the cam sensor. My assumption was that the cam sensor and magnet is under the timing cover and timing chain, am I wrong? If they replaced the cam sensor and magnet through a port why did it take 5.4 hours? Is this correct?

I have the shop manager, sales manager and tech giving me three different stories of how the replacement of the cam sensor and magnet was installed.

Thanks

[Tech II]

Sounds like someone is giving you the runaround......I think what they did was try the old JBWeld trick, where you remove the cam sensor, then through the hole where the cam sensor was, they rotate the cam until the missing magnet hole lines up with the hole for the cam sensor....then they grind the new magnet down to fit, and hold it in place with JB Weld.....sometimes it works, sometimes it doesn't.....but they should have explained to you that was what they were trying, because that is not the correct way to do it....it's a flat rate trick..... methinks it didn't work and now they want to charge you for the correct job....

Think they should do the job?

[88PA]

I have a 88 Park Av. with the 3.8 and I can tell you that replacing the timing chain and water pump is pretty major work. That being said, I simply don't know how a timing chain and especially water pump can cause a 41 code. Prior to changing out the timing chain at 195K miles mine was so far gone that it was slapping the cover and I didn't have any codes at all.

I will tell you that I had done the JB weld trick a couple years ago and it held up very well until I finally broke down and done it right. Also, I drove this car for months after said JB weld fix with the engine light on thinking the magnet had flown off when in fact all that was wrong was the cam sensor had come unplugged somehow. Check the wiring real good and make sure it's all plugged in and not bare someplace.

Sounds like unfortunately your Mechanics are raking you over the coals.

[82Stang]

Originally Posted by Tech II

it's a flat rate trick

Flat rate has turned many a good mechanic, bad!

[Tech II]

A good tech, if there is a chain/sprocket/tensioner problem on a 3.8, would recommend changing that magnet while he was in there....

[Pony Boy Midnight]

You have got to go to a reputable garage and speak to a knowledgeable group of technicians. That shop you are going to now is just bending you over! (so to speak)