Permanent Trouble Codes
Thread Starter
3rd Gear Member
Joined: Jul 2017
Posts: 849
From: AZ
Permanent Trouble Codes
Somewhere in my recent past work, I encountered information stating that beginning in 2009 all new vehicles sold must have the provision of storing certain codes which cannot be erased by usual means. Those "permanent" codes remain, causing CEL on, until Powertrain Control Module (PCM) determines the cause has been repaired and eliminated. At that time, PCM erases the code(s). Only PCM can do that.
I searched high and low and found no info on this. Does anyone have some knowledge about this?
08'MustangDude may just have info on this. Perhaps he can explain.. imp
I searched high and low and found no info on this. Does anyone have some knowledge about this?
08'MustangDude may just have info on this. Perhaps he can explain.. imp
Banned
Joined: Jan 2018
Posts: 2,327
From: Pennsylvania
There are some, but they are not Emissions related codes.
If you get a U0101, "Lost communication with TCM", for a Dodge anyway, the car will not
move until the code is cleared, even if the TCM is working. I still have it, a TCM that will
not wotk when it's cold. My Charger, the CEL, ESP/BAS lights would come on, and the
car would only move at idle speed after slamming into gear. If you throttled it, it would
warble from 800-900 over and over again. When it warmed up, the TCM would work,
but as long as the code was set, the car would not drive. So, I used my Tuner, and
cleared the code and it would immediately work.
I 100% verified it was the TCM by placing it in the frezzer on a hot summer day. From
the freezer to the car, U0101. After it warmed up to ambient temps, I would clear the
code, and the car ran fine. The Chargers with the NAG1 trans my Mercedes had
a separate TCM, where as the Dodge Trans was directly controlled by the ECU.
This also allowed people to hand you their TCM after a gear swap, and you could
change it to what they need, and put yours back in with no issues. Gear ratio is
solely stored in the TCM. If you have two TCMs, you can program both of them
for the gear ratio after the initial tune, then unmarry the tuner, and put the spare in,
and you are stock with the changed gear-set.
VW has tons of codes that store, and you can't clear them with a simple scan tool, you
need VCDS to do it. Most of them do not effect driveability though. U0101 is one
of them that does. VWs will go out of gear, and PRNDL will blink on the console,
varies with year....
If you get a U0101, "Lost communication with TCM", for a Dodge anyway, the car will not
move until the code is cleared, even if the TCM is working. I still have it, a TCM that will
not wotk when it's cold. My Charger, the CEL, ESP/BAS lights would come on, and the
car would only move at idle speed after slamming into gear. If you throttled it, it would
warble from 800-900 over and over again. When it warmed up, the TCM would work,
but as long as the code was set, the car would not drive. So, I used my Tuner, and
cleared the code and it would immediately work.
I 100% verified it was the TCM by placing it in the frezzer on a hot summer day. From
the freezer to the car, U0101. After it warmed up to ambient temps, I would clear the
code, and the car ran fine. The Chargers with the NAG1 trans my Mercedes had
a separate TCM, where as the Dodge Trans was directly controlled by the ECU.
This also allowed people to hand you their TCM after a gear swap, and you could
change it to what they need, and put yours back in with no issues. Gear ratio is
solely stored in the TCM. If you have two TCMs, you can program both of them
for the gear ratio after the initial tune, then unmarry the tuner, and put the spare in,
and you are stock with the changed gear-set.
VW has tons of codes that store, and you can't clear them with a simple scan tool, you
need VCDS to do it. Most of them do not effect driveability though. U0101 is one
of them that does. VWs will go out of gear, and PRNDL will blink on the console,
varies with year....
Thread Starter
3rd Gear Member
Joined: Jul 2017
Posts: 849
From: AZ
There are some, but they are not Emissions related codes.
If you get a U0101, "Lost communication with TCM", for a Dodge anyway, the car will not
move until the code is cleared, even if the TCM is working. I still have it, a TCM that will
not wotk when it's cold. My Charger, the CEL, ESP/BAS lights would come on, and the
car would only move at idle speed after slamming into gear. If you throttled it, it would
warble from 800-900 over and over again. When it warmed up, the TCM would work,
but as long as the code was set, the car would not drive. So, I used my Tuner, and
cleared the code and it would immediately work.
I 100% verified it was the TCM by placing it in the frezzer on a hot summer day. From
the freezer to the car, U0101. After it warmed up to ambient temps, I would clear the
code, and the car ran fine. The Chargers with the NAG1 trans my Mercedes had
a separate TCM, where as the Dodge Trans was directly controlled by the ECU.
This also allowed people to hand you their TCM after a gear swap, and you could
change it to what they need, and put yours back in with no issues. Gear ratio is
solely stored in the TCM. If you have two TCMs, you can program both of them
for the gear ratio after the initial tune, then unmarry the tuner, and put the spare in,
and you are stock with the changed gear-set.
VW has tons of codes that store, and you can't clear them with a simple scan tool, you
need VCDS to do it. Most of them do not effect driveability though. U0101 is one
of them that does. VWs will go out of gear, and PRNDL will blink on the console,
varies with year....
If you get a U0101, "Lost communication with TCM", for a Dodge anyway, the car will not
move until the code is cleared, even if the TCM is working. I still have it, a TCM that will
not wotk when it's cold. My Charger, the CEL, ESP/BAS lights would come on, and the
car would only move at idle speed after slamming into gear. If you throttled it, it would
warble from 800-900 over and over again. When it warmed up, the TCM would work,
but as long as the code was set, the car would not drive. So, I used my Tuner, and
cleared the code and it would immediately work.
I 100% verified it was the TCM by placing it in the frezzer on a hot summer day. From
the freezer to the car, U0101. After it warmed up to ambient temps, I would clear the
code, and the car ran fine. The Chargers with the NAG1 trans my Mercedes had
a separate TCM, where as the Dodge Trans was directly controlled by the ECU.
This also allowed people to hand you their TCM after a gear swap, and you could
change it to what they need, and put yours back in with no issues. Gear ratio is
solely stored in the TCM. If you have two TCMs, you can program both of them
for the gear ratio after the initial tune, then unmarry the tuner, and put the spare in,
and you are stock with the changed gear-set.
VW has tons of codes that store, and you can't clear them with a simple scan tool, you
need VCDS to do it. Most of them do not effect driveability though. U0101 is one
of them that does. VWs will go out of gear, and PRNDL will blink on the console,
varies with year....
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