AEM 30-4110 Bosch LSU4.9 Issues

[NickelSpeedShop]

What am i missing here?

I purchased an AEM 30-4110 to aid in tuning my truck and have gone through 3 sensors in about 2 months. I contacted AEM after the first failure and they had me do some diagnosing before they ended up sending me a replacement sensor under warranty. During this diagnosing AEM verified that my wiring is correct, the sensor is mounted in a good position at an acceptable angle and they claim that the testing I did proves that the controller is not to blame. In the meantime I purchased a genuine Bosch sensor from a reputable source. The 2nd sensor failed in the same fashion today while trying to tune, it lasted maybe 2 weeks with very limited run time. I installed the replacement that AEM sent and it lasted approximately 2 miles. I even installed a switch in line on the power to the unit to prevent the unit from commanding the heater until the truck is running. (so the heater wont run when I have key on- engine off) Im pulling my hair out at this point, when the sensor works it appears to read correctly but then i will be cruising at a fixed rpm and the reading will go lean until it reads "---". Im ready to bail on this system all together and stomach the $200 loss but im concerned because it seems that every wideband seems to use this same sensor. Do any of you guys have any other ideas of what i may be doing wrong?

[TheMechanic]

How does it look visually? Oil fouled? Coolant fouled? How are your ground circuits?
As a side note I wouldn't disable the heater. As they get hotter the resistance increases thereby lowering the current.

[NickelSpeedShop]

The sensor looks new, just slight discoloration on the stainless due to heat but nothing that alarms me.
The engine is a new GM unit with maybe 500 miles on it that has only been opened up to install a cam. It does not, to my knowledge, burn any oil or use any coolant.
The ground for the controller goes directly to the dash support, I have hooked it up with a jumper directly to the negative battery terminal but that made no difference so I determined that my under dash ground was sufficient. Power is through a 10a fuse to an ignition hot terminal on the under dash distribution block. The only reason I installed the switch was so the heater would not run while the truck is sitting without the engine running but i don?t even get a chance to test its function because the newest sensor failed on the first run. I have to be messing something up because there?s no way I have gotten 3 bad sensors in a row.

[TheMechanic]

The sensor looks new, just slight discoloration on the stainless due to heat but nothing that alarms me.
The engine is a new GM unit with maybe 500 miles on it that has only been opened up to install a cam. It does not, to my knowledge, burn any oil or use any coolant.
The ground for the controller goes directly to the dash support, I have hooked it up with a jumper directly to the negative battery terminal but that made no difference so I determined that my under dash ground was sufficient. Power is through a 10a fuse to an ignition hot terminal on the under dash distribution block. The only reason I installed the switch was so the heater would not run while the truck is sitting without the engine running but i don?t even get a chance to test its function because the newest sensor failed on the first run. I have to be messing something up because there?s no way I have gotten 3 bad sensors in a row.

Not necessarily. Over the last 5 or so years I have had a LOT of bad brand new parts. Some from the dealer and some are even AC Delco counterfeit. These are knock sensors, HO2s, MAF sensors, etc. Had one a year ago that I put 4... Yes 4 aftermarket steering boxes in a Silverado HD DMax and finally put in a factory twice the cost box and it fixed it. Each time my Kent Moore tool was telling me box was bad I started to doubt my tester. Have had several hydroboost from aftermarket that when you turn the wheel it applies the brakes. (bad spool valve). I will never use aftermarket boxes or hydroboost again.
I would call customer service again and tell them it was bad out of the box and ask if they want to replace the entire unit. Maybe it is overheating from to much/long heater time.

[NickelSpeedShop]

Well I purchased a $120 replacement sensor from a local store. It should be in tomorrow. At least this way I can look at it before accepting it. I am questioning if the 3 sensors I have had problems with are counterfeit.

The original sensor and the warranty replacement from aem are identical. They have no markings on the sensor body and the word ?Bosch? is not printed anywhere on the sensor or plug. There is a small logo that looks like the Bosch logo on the plug but I?m not super confident these are genuine.

The unit I sourced has a different luster on the stainless body, it?s looks like higher quality. The machining on the hex looks better and it has engraved text on the sensor body. The engraving says ?Germany? not ?Bosch? so it still is questionable. The plug again only has a small logo that looks like the Bosch logo but the word ?code? is misspelled as ?cobe? which is odd. And not German from my short research.

Genuine sensors on Boschs website say ?BoschLSU 4.9? on the body and have a pair of hashed machines into the peaks of the hex. We will see what my local store comes up with.

[TheMechanic]

Here is what I just google'd

This one has an actual number check
https://bimmerprofs.com/bosch-fake-genuine/

side by side comparison.
https://www.classiczcars.com/forums/...bosch-sensors/

https://www.dsmtuners.com/threads/fa...ensors.531538/

https://www.youtube.com/watch?v=lxzMynTJjE4


https://stangnet.com/mustang-forums/...deband.920599/

[blindsquirrel]

I even installed a switch in line on the power to the unit to prevent the unit from commanding the heater until the truck is running. (so the heater wont run when I have key on- engine off)

I don't think that's a great idea - at least, the sensors are not failing because of the heater being powered at KOEO. Running the heater is good for them, it helps burn off any deposits that really can kill a sensor. Heater circuit is controlled and monitored, it doesn't just apply constant power and ground all the time, it runs when needed to maintain the desired temp. Same as the factory narrowbands do.

[TheMechanic]

The unit I sourced has a different luster on the stainless body, it?s looks like higher quality. The machining on the hex looks better and it has engraved text on the sensor body. The engraving says ?Germany? not ?Bosch? so it still is questionable. The plug again only has a small logo that looks like the Bosch logo but the word ?code? is misspelled as ?cobe? which is odd. And not German from my short research.

h.

Look at the second link I posted. It might be the best for you.

side by side comparison.
https://www.classiczcars.com/forums/...bosch-sensors/

[NickelSpeedShop]

I don't think that's a great idea - at least, the sensors are not failing because of the heater being powered at KOEO. Running the heater is good for them, it helps burn off any deposits that really can kill a sensor. Heater circuit is controlled and monitored, it doesn't just apply constant power and ground all the time, it runs when needed to maintain the desired temp. Same as the factory narrowbands do.

Well it doesn't matter because I never used it.

[NickelSpeedShop]

I have actually read 2 or 3 of the links you put up and thats what made me start questioning the authenticity of what I have. According to these all 3 of my sensors are fakes. both units from AEM came with no paperwork (one in the kit with the controller and the other in a white, unmarked box with no paperwork). none of my units have the machining on the peaks of the hex and none of mine say the work "Bosch" on them anywhere. The unit I sourced came in a Bosch box with no hologram sticker and again has no Bosch branding on them anywhere.

[NickelSpeedShop]

Interesting update. I got the sensor from the local place today. I am very confident that the 3 I had received prior to this are indeed fake. the Bosch sensor says "Bosch LSU4.9" laser engraved on the metal housing and has slight differences from the other 3. I also looked at the other 3 and found inconsistencies between the original 3 units such as the shape of the tip and the crimping on the cold end. I installed the new sensor and verified that it functions. I will just have to give it some time to see how long it will last.

Thank you everyone for the help!