"BMW scan tool" vs "OBD-II" Scan Tool

[dowright82]

Hey guys - wanted a 2nd opinion on this.

Today a NEW mechanic who was diagnosing my evap leak (smoke test not easy to do in my garage) called me and said I had a cylinder 4 misfire code.

I thought this to be odd, because I own an obd-II scan tool and that's how I knew about my P0455 evap leak code, but have NEVER seen a cylinder misfire code.

He replied by saying he uses a BMW tool that shows "hidden codes" that my standard OBD-II scanner doesn't see. Is this possible?? Or is he totally pulling my leg??

[Tim95M3]

This is absolutely true. I have an OBDBook handheld for personal use, and sometimes it will show me different things than our AutoLogic or BMW GT-1 scan tools at my shop. Generic scan tools are always gonna give you a different description for a code, and even not bring up some codes.

[hefftone]

I agree. The Peake BMW Scan tool is definitely the way to go. I also have the "Torque" app on my android phone which works great on my wifes altima but is very hit or miss on the BMW. At least with the peake you know the exact code.

Just a little over a $100 on ebay nowadays.

[MauiM3Mania]

No doubt. The big dollar scanners used at dealers and independent shops cost more for a reason. A friend is a tech at an indie and before he picked up a GT-1 clone (a somewhat older BMW scan/tool) he only had a Snap-On at his disposal.

From what I have seen, it offers much more pertinent data. Compared to an AutoZone level scanner, it is night and day. He would suggest the difference is more like night and day on planet Mercury.

[merlinfe]

I'd think you'd feel a misfire and get a CEL at the very least. I also think that guys full of ish. Tell him you'll take the car elsewhere. If need be go to the dealer to dislodge any doubt otherwise go with your gut.

[Stephen Max]

You may be having a very occasional misfire that the ecu detects and records, but is not frequent enough to trigger a CEL. The BMW tool can monitor such things, whereas the generic tools don't.

[merlinfe]

Ok Stephen, I'll give you that. On my E90 there were "shadow" codes that showed up on the BT cable but couldn't be read by anything else. Just seems like the mechanic mysteriously coming up with it is suspect. I have a hard time trusting anyone making a profit when they tell you something not previously identified was effed up.

[bay707]

the peake tools are awesome and very user friendly.

[RisBMW]

Does the Peake tool display more codes than are available via the stomp test? (OBD1)