Accessing the GM OLM PID with a scantool

Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
Has anyone done this, specically with Alex Peper's OBD2 Vehicle Explorer? My mom's 2004 Malibu Classic does not have the GM OLM..at least there is no dashboard indicator or reset switch for it..but I wonder if the ECU still supports the "oil life remaining" PID and if it could be accessed with a scantool, and if it's still counting down... I might just have to bring my notebook PC down there and try it..
 

Al

Joined
Jun 8, 2002
Messages
19,302
Location
Elizabethtown, Pa
I don't think its a displayed value..but I could be wrong. I put it on my sons 2000 GrandAm and don't recall that value. I do have the enhanced version of GM on my ScanTool.
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
Alex Peper's website says that it supports the "Oil Life Remaining" PID enhanced GM data item. I'm going to try pulling that data this weekend, I'll summarize the results in this thread.
 
Joined
Jan 18, 2003
Messages
186
Location
An Alberta Garage
Check your user's manual. Some of the GM vehicles from that area have the OLM expressed as a percentage remaining as one of the functions of the odometer (eg: as you step through the settings by pressing on the odometer control stalk on the display you will display total distance, trip A, trip B, OLM).
 
Joined
Jun 12, 2003
Messages
342
Location
Limon, Co
Being it's a '04 im sure it has the OLM... Just not the DIC(Drivers Info Center). My '04 monte just lets you kow when to change but does not have the DIC unfortunatly.
 
Joined
Nov 6, 2003
Messages
1,251
Location
Akron, OH
brianl703: 4 miles to work is severe under most carmaker's definitions. "Most drives are under 10 minutes" is pretty common boilerplate.
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
Ford states that is only considered severe "when outside temperatures remain below freezing". GM says something like "especially when temperatures are below freezing". So I'm pretty sure that's severe in winter, not so sure about summer.
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
I checked the user's manual, it says nothing about the OLM. I too would have expected it to be in the odometer display, but I get "trip" and "total distance" as I push the button on the display, that's it. It has the same instrument cluster as the 2003-previous Malibu (which, as far as I can tell, did not come with the OLM either) and so what I think is that the instrument cluster does not have the ability to display the OLM, but the function is still enabled in the PCM and can be accessed with a scantool. Of course, if it is, I still have to figure out how to reset it...
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
The reason I'm wondering about the OLM is that the car is generally only driven 4 miles to work and 4 miles back home again, and I'm not sure if that's considered "severe" or not, so I'd like to see what the OLM says. Maybe I should just get an oil analysis done..
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
The GM OLM PID *is* accessible with Alex Peper's OBD2 Vehicle Explorer and does exist on the 2004 Chevrolet Malibu Classic. When I checked it today, it was at 0.5% oil life remaining, which apparently really means 0% oil life remaining. I'd considered the problem of how to reset it. Because this car doesn't "officially" have the GM OLM, no provision had been made to reset it: The button to push in the fusebox wasn't there, the trip odometer didn't support anything having to do with the OLM...using the radio to reset it like some GM cars do? Forget it, the base-model radio isn't that sophisticated and even if it were the uplevel radio it probably still couldn't do it. So I used Google to search for "GM OLM RESET" and found, in an article on http://www.gmtechlink.com a method that GM suggests for some models: Turn the ignition to on without starting the engine, then push the accelerator pedal to the floor 3 times within 5 seconds. I reasoned that this would most likely work, as the accelerator pedal is connected directly to the PCM wherin resides the GM OLM software and all of the other methods seem to go through the body control module first. So I tried it. It took a couple of tries, apparently if you go too fast it won't register and won't reset the OLM. Or maybe it needs more than 3 times..either way, I got it to reset by pushing the gas pedal to the floor several times. When it did reset the OLM, it went to 100.5% oil life remaining. I have no idea why it always adds .5% to the oil life remaining. I'm going to check it again in a couple of weeks and see how much it's dropped. That'll give me an idea of just how severe my mom's driving really is.
 

Win

Joined
Feb 5, 2003
Messages
4,704
Location
Arkansas
Brian, On my '04 GTO, the OLM is reset by fully depressing the accelerator twice within five seconds prior to starting. Maybe you were going too fast. Nice bit of work.
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
Today I checked the OLM PID in my mom's car and it has dropped to 98.5% (really 98%) in what I guesstimate is 50 miles of driving, so with the usage it's currently getting (short trips..it took a week to rack up 50 miles), the OLM will be at 0% in about 2500 miles.
 

Win

Joined
Feb 5, 2003
Messages
4,704
Location
Arkansas
Will the simple scan tools access this data, or does it take one of the high end ones?
 
Joined
Apr 5, 2004
Messages
9,427
Location
Pensacola & Vero Beach FL
quote:
Originally posted by brianl703: Today I checked the OLM PID in my mom's car and it has dropped to 98.5% (really 98%) in what I guesstimate is 50 miles of driving, so with the usage it's currently getting (short trips..it took a week to rack up 50 miles), the OLM will be at 0% in about 2500 miles.
Brian: A great piece of investigative work, congrats. I wonder, however, since the feature appears to be a dormant vestige of programming that remains in this low-end car only because it's probably more expensive to remove it, whether the data it generates is valid. I'm certainly not suggesting the data is per se worthless and should be ignored, but I'd recommend some careful cross-checking against other info sources before relying on this data. Even in fairly harsh service, I'd be surprised to see the GMOLM calling for a change at only 2.5k miles. I owned my GMOLM-equipped 3.8L in my pre-BITOG days, when I'd change oil every 5k miles, regardless. At 5k miles, I never saw it below about 40% life remaining. Again, great work, and please let us know how the data plays out. [Cheers!]
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
Simple, handheld scan tools will not be able to access this data. You could do it with the Scangauge but you need to know what to send and how to interpret the data; someone could figure that out. I'm thinking about doing that, since I have a Scangauge. I'm using Alex Peper's Vehicle Explorer which can access this data..if you have a notebook/laptop, even if it's a 386 on Windows 3.1 (his software is optimized to run well even on older laptops), I beleive it to be the best scantool out there. Even if I didn't have a laptop, I'd just make a long serial cable and use it with my desktop. I believe I can put Vehicle Explorer in a "sniffer" mode and see what it sends to retrieve the OLM PID, as well as what it gets back. Once I have that, I ought to be able to use it to get the same data using the Scangauge.
 

brianl703

Thread starter
Joined
May 7, 2004
Messages
10,910
Location
Nokesville, VA
quote:
Originally posted by ekpolk: I wonder, however, since the feature appears to be a dormant vestige of programming that remains in this low-end car only because it's probably more expensive to remove it, whether the data it generates is valid.
I've considered that..the 2004 Pontiac Grand Am with the 2.2L Ecotec is also an N-body (which officially has the GM OLM) and seems to have the same ECU hardware-wise and software-wise, at least to the point of view of the Vehicle Explorer..I access the data by selecting 2004 Ecotec N-body which covers both the Grand Am and the Malibu Classic. I (unfortunately) didn't make a note of the mileage so 50 miles is a guesstimate based on 5 trips to/from work..it could easily be double that. I'll continue to check it every week or two, and next time I'll note the mileage.
 
Top