Posted: Sun Jun 22, 2008 12:03 am Post subject: need help with transmission problem Magna


I've just replaced the auto transmission in a 2000 TJ Magna, with a (tiptronic) 2003 TL Magna transmission, from the outside they are completely identical.

but wait on the inside there is one small difference I noticed that when installing it, where the Speedometer gear is on the 2000 TJ on the 2003 it has a plastic covered I took it of and installed the SPEEDOMETER GEAR, but inside there is no wheel/gear to run/drive the SPEEDOMETER GEAR so I don't get a reading on the dashboard on the A/T ECU doesn't get a reading which makes it run in Fail Safe mode.

I now have a flashing N on the 2000 TJ Magna, which means that the transmission is in FAIL SAFE Operation and is locked i 3rd gear

I replaced the input and output shaft speed sensor from another Magna this didn't fix it, so I'm quite sure the problem is the SPEEDOMETER GEAR

Does anyone know how the speedo works on the 2002+ Magna's

Does anyone have a "easy" solution for this, is there anything I can take of the donor car (A/T ECU) or will the tiptronic shift lever make a difference?

Any help is appreciated Thanks Alcs

On the image nr 12 is SPEEDOMETER GEAR
nr 8 + nr 9 Input/Output shaft speed sensor


Attached thumbnail(s)

saw you problems on the other forum

http://www.mitsubishiclubaustralia.com/for...opic.php?t=6590

:beer:

Well firstly the speedometer there are diffrences , the original transmission yu had is an F4A51 , with a geared speedo , and like the W5A51/52/54 like mine and 2002 up F4A51 has a magnetic hall affect speed sensor. Its not as simple as an ECU swap. Like my 97 with the W5A5 series with Super INVECS II , models with "Tiptronic" used a whole diffrent sensor and power layout to the transmission , thus even though the plug ins were not very diffrent. The hall effect speedo sensor was more linear and precise , in making rev based pressure calculations for shifting. This is why the transmission is not permitting a shift , because there is no power even going to the shift solenoids , or the so claimed "Fail Safe" if yu say. Regardless , if the transmission ECU is getting a reading frum the input shaft and output shaft sensors it will still be able to calculate shifts without the speedometer , but it will shift with inaccurate shift pressure . If the ECU reads input frum the input and output shaft speed sensors , and the transmission solenoid wiring plug in is not plugged into the input plug in or vice versa , the ECU will still start off the transmission in first gear , and shift accordinglly if the input shaft and output shaft speed and pressure control pattern are within range even without having a present speedometer reading. The only way the transmission starts off in third gear is if , the control solenoid plug in is loose, transmission fuse is blown, plug in is in wrong spot etc. The valve body has open third passage in teh transmission while in the D range , so when the shift solenoids and pressure control are not getting power , the valve body in the transmission cannot divert fluid to the high end shift clutches. So in fact its not a special "Fail Safe Mode" its merely teh way teh valve body in the transmission is designed for diverting pressure. Check yur plug ins near the tranny , but this will not simply fix yur problem

KiT TeUnG 2549

Will alco need an auto electrician to swap wires

at the TCU connections of the tranny

to get the speedo working ?

When I start the car everything works normal, idle is normal the N on the dashboard displays normal. When Start driving Reverse works as normal in D it starts in 1st gear, shifts reasonble smooth into 2nd after hitting about 30km it jumps "klonks" into 3rd
The N on the dashboard flashes and it stays in 3rd gear the rest of the ride until I turn the car off and the same thing over again.

I red in a mithubishi manual that this happens when the input shaft speed sensor doesn't work.

The Speedometer gear in the image attached is fine of the 2000 tj F4A51 transmission,
but inside the transmission case on the old transmission there is a gear around the drive shaft going into the transmission, this gear is not there on the new 2003 transmission,

so what I am wondering is where doe the 2003 Magna get's its speed reading from ?

Thanks Alcs

Attached thumbnail(s)

On top of the speedometer gear there is a sensor, the wholespeedometer gear and sensor is not there on a 2003 transmission

Attached thumbnail(s)

the input and output shaft speed sensor are identical and in the same spot on both transmission (Apears to be from the outside)



Attached thumbnail(s)

Okies let meeh pace this for yu , Ill explain my car for instance. Its a W5A5 series , much like the F4A5 and F5A5 series , with INVECS II and TIPTRONIC features , the reason there isnt a speed sensor geared as non INVECS and TIPRONIC models is because , one , it relies heavilly on the input and output sensors , also , as INVECS and TIPTRONIC rely on the hall effet of the speed sensors on the wheels. The wheel speed sensors that are used for the anti lock system are also used in conjunction with the Tiptronic and INVECS , thus iliminating the transmission speed sensor , since the TCM is using the speed sensor readings frum the speed sensors that are located at each wheel. This way especially in my model which is AWD it can calculate shift pressure and shift points by reading the individual wheel speeds, and this is the case for yu also, it can shift accordinglly by the transmission input and output shaft sensors to a certain degree but can not properlly calculate shift up and down points after because of the transmission design. The onlee way to get this working as old is to take the linear output axle drive frum the old transmission and put it in the newer one, Thus there will still eb a shifting pressure issue at lower gears like 3-4 and 4th over run gears. The thing is that with transmission that use INVECS and Tiptronis the read wheel speed frum the wheel speed sensors , which helps the TCM evaluate a driving pattern.

The reason for the clonk is that it can no longer evaluate a drive speed , and that the input shaft and output shaft are above the regulated limit without a speedo reading and it can no longer evaluate bwuts a proper shifting pressure

That doesn't sound like I'll be able to get it to work unless I rewire most of the car, I saw the wheel speed sensor on a manual of a 380 Magna, It doesn't look like I 'll be able to swap all that over to the other car.

I think I might have to pull the tranny again and swap it for a different model. 2nd time round should be easier.

On another note how much transmission fluid do you have to put in the torque converter? I previous put it vertical, (as it is installed attached to the motor) and then filled it with oil until it started running out is this right, also is there an easy way o drain them or just put them upside down, and last there is no difference between the 2003 and 200 model is there? (just in case)

Also interesting I red that the Mitsubishi Transmission oil is cheaper, I spend $50 aud on 4 liter Castrol oil before, see if I can find the mitsubishi stuf.

off topic: Today I was driving to work all the way in 3rd gear, (works just a slow take off) and the car started to stutter I was worried that I completely buggered the transmission by driving it in this condition, but"luckily" I just run out of petrol.

Thanks for your responses KiT, magna buff and chain

Regards Alco

Sorry is not work out for yu , Like i say there is actually a way to get yur model tranny to work but it would require re-removing the transmisson case and opening it to put in the reluctor ring , but the old transmission would be needed and the diffrential portion would need to be swapped as the reluctor ring is non removable and on that section. And for the most part the transmission would operate like the old one. The TQ if its empty should take about 3.5/4 quarts of fluid. Like say yu see Many INVECS and Tiptronic use ABS and Traction Control in conjunction as one setups is why on models with either feature as Tiptronic or INVECS II the tranny speed sensor is discontinued cause it uses the wjheel speed sensors to get a more accurate reading

KiT TeUnG 2549
thank for you input and knowledge

that was a tuff one :banana:

NO problem , we are all here to help and thanks yu also