Hi all,

I'm fairly certain the TCM on our 02 Accent 1.6L is the source of our transmission problem. I've picked up two used TCMs with matching part numbers, one from an 01 and one from an 02. When I pop these on the car it will go in to park, reverse, and drive but won't switch to any gears while in drive. If I drive the car without a TCM in it at all I get the same result. So my immediate thought is that the car is not even recognizing these two other TCMs.

My research so far has told me it is best to flash a TCM before putting it in an Accent but can be done without flashing, you may just experience problems shifting. My wife's father did this in the past and was able to get another TCM to work, just not very well. However the Hyundai dealership told me the TCM MUST be flashed because it has the VIN of another car stored in it and thus won't communicate with mine.

Does anybody here know the actual facts about placing a different TCM in an Accent?

Thanks!

 

On these old models, the tcm and PCM are plug and play modules. No programming involved. They can however be reflashed with available updates. What fault codes do you have. I have worked on these cars for years and have never had a tcm problem. These transmissions are notorious for problems. We used to stock them like light bulbs.! You need to have car scanned with a good scanner that can read the tcm side for specific fail code. Sounds to like car is in fail safe mode, stuck in 3rd gear. Also check your fuses. Room lamp fuse does supply power to tcm...

 

I think your logic is off. If the car is doing the same thing with 3 different TCM's then that leads me to believe the TCM is NOT the problem. I think you have an internal issue or a problem with a different electrical component.

Time to let a REAL mechanic look at it.

 

It can be pretty trying sometimes to convince people who used to switch parts from any vehicle in a salvage yard and got away with it in the past. Now , the manufacturers can make changes to operating modes pretty easily by just reprogramming / reflashing the PCM . If the person doing the usual "old" ways of swapping parts is not aware of this , it can become a real hair pulling adventure. I believe that is where the REAL mechanic/technician comes to the rescue.

 

Hi,

Sorry for the delayed response. I really appreciate the info!

My understanding was that these TCMs were plug and play as well, but when I put two other TCMs in my car, the car would not switch any gears at all. I even drove the car around the block without a TCM in it and had the same result. To me that says that the car will not accept these TCMs at all. Any ideas why? (My current TCM will switch gears just very poorly and with gear skipping.)

I've had the car scanned at several independent transmission shops and their transmissions scanners can't communicate with my TCM. I also had it scanned on the GDS at a Hyundai dealership. This is what I got back:

p0340 - Camshaft Position Sensor A Circuit Malfunction
p0650 - Malfunction Indicator Lamp Control Circuit
p1765 - Torque Reduction Request Malfunction
p1693 - Immobilizer Transponder Fail
AT - Automatic Transaxle: Communication Fail / Check whether system is install...

http://s27.postimg.org/6yegafm6r/Page_1_GDS.jpg - Here's a scan of my GDS printout.

I don't believe 0340 relates to the trans issue. And I don't have any immobolizer tech on the car so I'm not certain about 1693. The bulb is gone for the MIL so that explains 0650.

The Hyundai tech pointed to 1765 being the problem and said the entire transmissions has to be replaced. I'm having trouble research exactly what causes the torque reduction request malfunction. Any details?

The code that seems strange to me is "AT - Automatic Transaxle: Communication Fail". The Hyundai tech said this is due to my car not having an optional feature installed. He stated if there was a problem with the TCM it would give us a code, yet it gave no codes. And since all other transmission scanners can't communicate with my TCM it still seems like this may be a TCM problem.

I apprecaite any insight you may have!

 

Hi Nova,

My current TCM, the one that the car came with, does function to a degree. It has hard shifts, skips gears, and according to the Hyundai tech, is trying to engage multiple gears at once. Reverse is rough as well.

When I placed the two other TCMs in the car I had no response at all. The car will park, reverse, and go in to drive. But once in drive it will not shift through any gears. I drove the car without a TCM in it at all and had the same result. Looks like it won't even acknowledge these other TCMs. Any thoughts?

 

Hey guys,

Have an Accent that has been having issues with shifting for some time now. I have been doing troubleshooting back and forth between physical and electrical issues. I just came across some more info that makes believe it may be electrical.

I've been able to clear all codes on the car but two. P1765 and P1693.

Most scanners will tell you P1693 is an "Immobilizer Transponder" issue. The only problem is my car does not have an immobilizer, only 2002 Canadian Accents do. This info comes from the dealership.

The GDS scanner says P1693 is a "TCM Malfunction Indicator Lamp (MIL) Request Line..." I'm assuming there is more to this line but it's cut off on the print out. Does this code mean there is a communication problem with the TCM or that the TCM is just requesting the check engine light to come on?

I went to a few dealerships to inquire about this and both said they don't even have a P1693 listed in their database for my car. In fact 1999-2003 is completely empty from there DB. They had to look at a 2004 accent code list for reference.

The second code is P1765. All scanners, including the GDS, have said this is a "Torque Reduction Request Malfunction." Initially I was told this means my transmission is bad. Which is confusing to me because it's listed as an engine code. After doing further hunting I was told by Hyundai the possible cause of this could be "contact resistance connectors" or a "faulty PCM".

I've also seen p1765 listed online as "TCS-ITM CAN Communication Line" with the suggested remedy of checking the line from TCM (terminal C37-2-17 white/black) to ECM (terminal C26-10).

I've had two used PCMs and another used TCM flashed and installed at the dealership with no change in performance. Could it be as simple as a single bad wire?

I would love your guys feedback because I'm really in the dark on this and even Hyundai hasn't been able to answer my questions!

Best,
Nick

 

Hi guys,

My 2002 Accent 1.6L was having shifting issues that I was relatively sure were electronics related. I tried different ECMs and TCMs on the car, checked wires under the dash from pin-outs, etc. No luck. I finally had the transmission rebuilt. On the first time out from the trans shop the car would not shift. After that it did and was actually running okay when I took it for some test drives. But it started to hard shift coming down from either 2 to 1 or 1 to stop. And it just recently did a hard shift while shifting up around 2 or 3. This is the problem it had before and it looks like its coming back.

Trans shop computer can't pull codes from the TCM (the TCM seems finicky and won't always talk with some computers - it has and hasn't on their SnapOn). However the engine codes were p1765 (torque reduction) and p0340 (camshaft position sensor). These codes have always been there no matter what work Hyundai or anybody else did. However this time the mechanic showed me that both codes are referring to grounding issues.

I had the car taken to an auto electrics shop and they looked at all grounds/power and verified they are good. However, they plugged right in to the trans (going around the TCM) and were able to verify that the Pressure Control Solenoid A has continuity but does not actuate.

Trans shop says they replace it and shouldn't be a problem yet electrics shop showing there is.

Have any of you guys had experience with this? Do you know what elements of the shifting or which gears the Pressure Control Solenoid A controls?

Thanks so much!