Want to remove/disable your rear O2 sensor without a CEL? Here's how..
May 6, 2008, 01:40 PM
#274
I've been trying to get at this heater check routine from a few different angles. Today, I think I found the periphery bit that controls the O2 heater check. It appears to be periphery2, bit 11. Not sure what effect it will have on the OBD-II test readiness state. Here's what to do:
Change Periphery2 from EFDF to E7DF
If I am interpretting the ROM code correctly, there is no way to disable just the rear O2 heater. This will disable both the front and rear O2 heater checks, so beware of that limitation. If someone could try this and report back to me, I would appreciate it. Also, could you use ScanTech to observe the "Readiness" condition for the heater check?
Change Periphery2 from EFDF to E7DF
If I am interpretting the ROM code correctly, there is no way to disable just the rear O2 heater. This will disable both the front and rear O2 heater checks, so beware of that limitation. If someone could try this and report back to me, I would appreciate it. Also, could you use ScanTech to observe the "Readiness" condition for the heater check?
Here's scantech:
This is my xml for periphery2 on 88590015, just to make sure its correct..
<table name="ECU Periphery2" category="Misc" address="fca" type="1D" level="1" scaling="Hex16"/>
May 6, 2008, 02:05 PM
#275
I took a little break from work. Changed Periphery2 to E7DF and went for a drive. Didn't get a CEL. That's what I care about, so it seems to be working? I'm going to leave my resistor disconnected
Here's scantech:
This is my xml for periphery2 on 88590015, just to make sure its correct..
<table name="ECU Periphery2" category="Misc" address="fca" type="1D" level="1" scaling="Hex16"/>
Here's scantech:
This is my xml for periphery2 on 88590015, just to make sure its correct..
<table name="ECU Periphery2" category="Misc" address="fca" type="1D" level="1" scaling="Hex16"/>
edit: shouldn't your address=0xFFFF6BB8 ??? or am i misunderstanding that the periphery bits get written to the chunk starting at FFFF6BB2
Last edited by EvoBroMA; May 6, 2008 at 02:19 PM.
May 6, 2008, 02:22 PM
#276
Yes, FFFF6BB8 is the RAM address where it is held when the car is running. But the value is read from FCA when the car is started, so FCA is the one to change.
May 6, 2008, 02:51 PM
#277
It could be the "drive it around" thing, but probably not. I think I can fix the readiness issue too. Just need more time to study things.
Yes, FFFF6BB8 is the RAM address where it is held when the car is running. But the value is read from FCA when the car is started, so FCA is the one to change.
Yes, FFFF6BB8 is the RAM address where it is held when the car is running. But the value is read from FCA when the car is started, so FCA is the one to change.
May 7, 2008, 07:47 AM
#280
May 9, 2008, 08:33 AM
#281
I took a little break from work. Changed Periphery2 to E7DF and went for a drive. Didn't get a CEL. That's what I care about, so it seems to be working? I'm going to leave my resistor disconnected
Here's scantech:
This is my xml for periphery2 on 88590015, just to make sure its correct..
<table name="ECU Periphery2" category="Misc" address="fca" type="1D" level="1" scaling="Hex16"/>
Here's scantech:
This is my xml for periphery2 on 88590015, just to make sure its correct..
<table name="ECU Periphery2" category="Misc" address="fca" type="1D" level="1" scaling="Hex16"/>
I tried this last night on an a friend's IX, worked perfect. Good work mrfred!
May 9, 2008, 11:08 AM
#282
mrfred is still working on mapping all the periphery bits, but he said he will work on the readiness codes soon.
Thanks again mrfred
May 12, 2008, 11:10 AM
#284
I've been trying to get at this heater check routine from a few different angles. Today, I think I found the periphery bit that controls the O2 heater check. It appears to be periphery2, bit 11. Not sure what effect it will have on the OBD-II test readiness state. Here's what to do:
Change Periphery2 from EFDF to E7DF
If I am interpretting the ROM code correctly, there is no way to disable just the rear O2 heater. This will disable both the front and rear O2 heater checks, so beware of that limitation. If someone could try this and report back to me, I would appreciate it. Also, could you use ScanTech to observe the "Readiness" condition for the heater check?
Change Periphery2 from EFDF to E7DF
If I am interpretting the ROM code correctly, there is no way to disable just the rear O2 heater. This will disable both the front and rear O2 heater checks, so beware of that limitation. If someone could try this and report back to me, I would appreciate it. Also, could you use ScanTech to observe the "Readiness" condition for the heater check?
I have noticed that usually different ROM IDs carry different values for things such as 2 byte load, 2 byte RPM, etc....should I be worried that this code above was for ROM ID 88590015 or are the Periphery codes universal for the USDM Evos?
BTW...I am also using the Rear o2 sim patch for my ROM ID found in this link... https://www.evolutionm.net/forums/sh...d.php?t=333820
Last edited by alan678; May 12, 2008 at 11:23 AM.
May 12, 2008, 02:31 PM
#285
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Seems like Periphery2 for ROM ID 96940011 reads the same stock value as above (EFDF) I changed mine to the updated value (E7DF) and will report back later on today...
I have noticed that usually different ROM IDs carry different values for things such as 2 byte load, 2 byte RPM, etc....should I be worried that this code above was for ROM ID 88590015 or are the Periphery codes universal for the USDM Evos?
BTW...I am also using the Rear o2 sim patch for my ROM ID found in this link... https://www.evolutionm.net/forums/sh...d.php?t=333820
I have noticed that usually different ROM IDs carry different values for things such as 2 byte load, 2 byte RPM, etc....should I be worried that this code above was for ROM ID 88590015 or are the Periphery codes universal for the USDM Evos?
BTW...I am also using the Rear o2 sim patch for my ROM ID found in this link... https://www.evolutionm.net/forums/sh...d.php?t=333820
So let me know if it works for you, I really want this to work!