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01m part 6 http://forums.tdiclub.com/showthread.php?t=402087
There are some discrepancies "out there" in the understanding of P0740 code in mk 4 car especially with 01m.
If you have access to vagcom then please use it to diagnose your 01m. If you do not, and your going to diagnose your car with some OBDII gadget then you need to understand what P0740 means.
Take a look at the following link. (the link is no good any more)
http://www.iequus.com/dtc
Punch in Vw and P0740 in the Equus code definition site and their definition will read "TCC Solenoid Circuit Malfunction". Most definitions for P0740 will read this way including if your using some full fledged "scanners" that are sold. This is a poor definition at best and a completely wrong and misleading definition at worst. A "solenoid circuit" code would be an electrical problem, this is NOT what P0740 is. See 01m part 5 solenoids. Link below
https://forums.tdiclub.com/showthread.php?t=334614
Vag com & Ross-Tech site shows the definition of 01192 as "Torque Converter Lock-Up Clutch: Mechanical Malfunction". 01192 corresponds directly to P0740. (meaning its the same code!) "Torque Converter Lock-Up Clutch: Mechanical Malfunction" is the correct definition of P0740 code.
Ross tech wiki for 01192 code below.
http://wiki.ross-tech.com/wiki/index.php/01192
The ross tech wiki shows possible causes as
1. Torque Converter Lock-Up Clutch faulty
2. Valve Body faulty
3. Internal Failure in Transmission
This means that P0740 (and 01192) would be repaired by fixing something mechanical NOT electrical stuff, with one exception of a stuck off TCC solenoid. Not very common in real world experience as I've only saw this once. see 01m part 5 solenoids in the section titled "stuck solenoid example 2" for explanation of this.
So people commonly want to treat a P0740 code as something electrical or as a "solenoid" issue. Lots of times they get this code, buy a solenoid and waste time and money replacing the solenoid, harness or other electrical parts that will not fix it. (solenoid, harness, computer ect)
I typed this here so that when I get questions that have this incorrect assumption, I can just send them the link to this thread.
If your car truly had a problem with the electrical circuit to the TCC solenoid it would trigger a code 00294 n94 solenoid circuit code. "open or short" or "short to ground" ect. see ross tech link below. The OBDII equivalant for 00294 is P0748 see equus code definition link again and punch in Vw and P0748 and you get "Pressure Control Solenoid A Electrical".
http://wiki.ross-tech.com/wiki/index.php/00264
So in summary..
P0740 is not a solenoid circuit trouble code.
P0740 means the computer can "see" a slip, by comparing the engine rpm to the G38 speed sensor. If you dont understand this read other 01m series threads.
There are some other makes that have this same type of OBDII code definition discrepancy, and on some Fords this discrepancy is in their own service info as well.
There are some discrepancies "out there" in the understanding of P0740 code in mk 4 car especially with 01m.
If you have access to vagcom then please use it to diagnose your 01m. If you do not, and your going to diagnose your car with some OBDII gadget then you need to understand what P0740 means.
Take a look at the following link. (the link is no good any more)
http://www.iequus.com/dtc
Punch in Vw and P0740 in the Equus code definition site and their definition will read "TCC Solenoid Circuit Malfunction". Most definitions for P0740 will read this way including if your using some full fledged "scanners" that are sold. This is a poor definition at best and a completely wrong and misleading definition at worst. A "solenoid circuit" code would be an electrical problem, this is NOT what P0740 is. See 01m part 5 solenoids. Link below
https://forums.tdiclub.com/showthread.php?t=334614
Vag com & Ross-Tech site shows the definition of 01192 as "Torque Converter Lock-Up Clutch: Mechanical Malfunction". 01192 corresponds directly to P0740. (meaning its the same code!) "Torque Converter Lock-Up Clutch: Mechanical Malfunction" is the correct definition of P0740 code.
Ross tech wiki for 01192 code below.
http://wiki.ross-tech.com/wiki/index.php/01192
The ross tech wiki shows possible causes as
1. Torque Converter Lock-Up Clutch faulty
2. Valve Body faulty
3. Internal Failure in Transmission
This means that P0740 (and 01192) would be repaired by fixing something mechanical NOT electrical stuff, with one exception of a stuck off TCC solenoid. Not very common in real world experience as I've only saw this once. see 01m part 5 solenoids in the section titled "stuck solenoid example 2" for explanation of this.
So people commonly want to treat a P0740 code as something electrical or as a "solenoid" issue. Lots of times they get this code, buy a solenoid and waste time and money replacing the solenoid, harness or other electrical parts that will not fix it. (solenoid, harness, computer ect)
I typed this here so that when I get questions that have this incorrect assumption, I can just send them the link to this thread.
If your car truly had a problem with the electrical circuit to the TCC solenoid it would trigger a code 00294 n94 solenoid circuit code. "open or short" or "short to ground" ect. see ross tech link below. The OBDII equivalant for 00294 is P0748 see equus code definition link again and punch in Vw and P0748 and you get "Pressure Control Solenoid A Electrical".
http://wiki.ross-tech.com/wiki/index.php/00264
So in summary..
P0740 is not a solenoid circuit trouble code.
P0740 means the computer can "see" a slip, by comparing the engine rpm to the G38 speed sensor. If you dont understand this read other 01m series threads.
There are some other makes that have this same type of OBDII code definition discrepancy, and on some Fords this discrepancy is in their own service info as well.
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