RX - 1st Gen (1999-2003) Discussion topics related to the 1999 -2003 RX300 models

Help -Transmission problems due to computer?!

Old 01-26-10, 10:00 AM
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lexusct
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Unhappy Help -Transmission problems due to computer?!

I have a 2001 RX 300 AWD with 120k. The transmission was having problems shifting into 2nd gear (slipping and banging). I took it to a transmission shop prior to Thanksgiving and had the transmission rebuilt.
New assembly set - $400
New band - $55
Exchange rebuilt torque converter - $300
New gear train assembly - $990
New bushing kit – $50
New thrust kit - $50
Fluid, Filter and labor

Since the car has not been shifting right and has been back 3 times.
1. Problem: slipping and banging into 2nd gear (similar to initial problem). Solution: Reprogram memory.
2. Problem: Dropping in and out of gear at highway speeds (55 mph +). Solution: Clean debris from solenoids.
3. Problem: intermittent slipping/banging into 2nd gear. Solution: Add fluid to lubricate new and old parts.
4. Problem: Continued slipping/ banging into 2nd gear, no longer intermittent! Solution: ???

Today the mechanic is saying the problem is with the computer which controls how and when the car shifts. He thinks the fix is to take the car to Toyota/Lexus to reflash the memory but won't guarantee it would solve the problem. If the reflash doesn’t work the computer needs to be replaced!

Given the types of problems with the shifting does this sound right?!
Old 01-26-10, 11:31 AM
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sktn77a
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So their diagnosis was incorrect and the problem was never corrected. And now they are telling you to go away? What was the total bill (inlcuding labor and fluids/filters)?

I would take it to the Lexus dealer and ask their opinion. They should know if the problem is with the ECU or the transmission. I feel your pain!
Old 01-26-10, 12:18 PM
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Lexmex
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Originally Posted by lexusct
I have a 2001 RX 300 AWD with 120k. The transmission was having problems shifting into 2nd gear (slipping and banging). I took it to a transmission shop prior to Thanksgiving and had the transmission rebuilt.
New assembly set - $400
New band - $55
Exchange rebuilt torque converter - $300
New gear train assembly - $990
New bushing kit – $50
New thrust kit - $50
Fluid, Filter and labor

Since the car has not been shifting right and has been back 3 times.
1. Problem: slipping and banging into 2nd gear (similar to initial problem). Solution: Reprogram memory.
2. Problem: Dropping in and out of gear at highway speeds (55 mph +). Solution: Clean debris from solenoids.
3. Problem: intermittent slipping/banging into 2nd gear. Solution: Add fluid to lubricate new and old parts.
4. Problem: Continued slipping/ banging into 2nd gear, no longer intermittent! Solution: ???

Today the mechanic is saying the problem is with the computer which controls how and when the car shifts. He thinks the fix is to take the car to Toyota/Lexus to reflash the memory but won't guarantee it would solve the problem. If the reflash doesn’t work the computer needs to be replaced!

Given the types of problems with the shifting does this sound right?!
A couple of possibilities.

1. Check the fluid level. When my uncle and I did transmission work back in Mexico, we ran into that when we put everything back together. Turned out we though the fluid level was correct and we were off by 2 quarts and it did similar to what was described, BUT

even after we did that we still had some issues related to

2. Electrical Grounding. For some reason we stupidly realized that since we had the transmission painted (there were some valid reasons for painting it that I won't get into but you can read about on my car domain page below) that the grounds to the transmission were not coming in contact with anything other than paint. However, in your case, I'd make sure they're on tight (with no dirt or anything else to come in the way).

I can add that the banging described was more apparent on the street and not so much with our testing on the highway. Not sure what your experience was, but consider the fluid level because often they can screw that up.
Old 01-26-10, 12:19 PM
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lexusct
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The total cost was $3,600. The work is under warranty and the shop has been very apologetic about the call-backs and seems sincere in trying to fix it. My concern is that each time the fix fails I am doing additional damage to my repaired transmission.
Also I do not want to keep doing this by trial and error.
The work is under warranty by the shop and if I go somewhere else it will void the warranty.

Is there any easy test to determine if the problem is the ECU. I seem to recall the mechanic doing an analysis during the inital diagnostics.
Old 01-26-10, 12:38 PM
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hypervish
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Make sure the transmission was filled with Toyota ATF-IV.
Old 01-26-10, 12:45 PM
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Lexmex
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Originally Posted by lexusct
The total cost was $3,600. The work is under warranty and the shop has been very apologetic about the call-backs and seems sincere in trying to fix it. My concern is that each time the fix fails I am doing additional damage to my repaired transmission.
Also I do not want to keep doing this by trial and error.
The work is under warranty by the shop and if I go somewhere else it will void the warranty.

Is there any easy test to determine if the problem is the ECU. I seem to recall the mechanic doing an analysis during the inital diagnostics.
There are ways of checking the voltages(s) on the ECM, but it depends on the issue at hand. There is significant part of volume 1 of the RX300 service manual and the entire diagnostic to that section is 50 pages alone including showing the electrical connections for each problem regarding transmission codes.
Old 05-30-13, 08:13 PM
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FtMyersLex
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Angry Transmission problems banging into gear & more

Originally Posted by lexusct
I have a 2001 RX 300 AWD with 120k. The transmission was having problems shifting into 2nd gear (slipping and banging). I took it to a transmission shop prior to Thanksgiving and had the transmission rebuilt.
New assembly set - $400
New band - $55
Exchange rebuilt torque converter - $300
New gear train assembly - $990
New bushing kit – $50
New thrust kit - $50
Fluid, Filter and labor

Since the car has not been shifting right and has been back 3 times.
1. Problem: slipping and banging into 2nd gear (similar to initial problem). Solution: Reprogram memory.
2. Problem: Dropping in and out of gear at highway speeds (55 mph +). Solution: Clean debris from solenoids.
3. Problem: intermittent slipping/banging into 2nd gear. Solution: Add fluid to lubricate new and old parts.
4. Problem: Continued slipping/ banging into 2nd gear, no longer intermittent! Solution: ???

Today the mechanic is saying the problem is with the computer which controls how and when the car shifts. He thinks the fix is to take the car to Toyota/Lexus to reflash the memory but won't guarantee it would solve the problem. If the reflash doesn’t work the computer needs to be replaced!

Given the types of problems with the shifting does this sound right?!
I had the similar problems & multiple trips to the transmission shop with multiple "rebuilds". Severe shifting problems between gears. To make a long story short after replacing the computer a mechanic decided to check the wires and found a bad ground wire from the computer. After replacing the wire the transmission shifted better but was kind of "banging" into 1st gear when first starting out in the morning or when sitting for a long time and occasionally in reverse. Transmission shop is still trying to find that problem... I will also add that both the front differential and rear differential gave out during this period, I believe it was because of the shifting problems.. I now have more invested in the vehicle than it is worth!! 160k miles..
Old 05-31-13, 08:35 AM
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Lexmex
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Originally Posted by FtMyersLex
I had the similar problems & multiple trips to the transmission shop with multiple "rebuilds". Severe shifting problems between gears. To make a long story short after replacing the computer a mechanic decided to check the wires and found a bad ground wire from the computer. After replacing the wire the transmission shifted better but was kind of "banging" into 1st gear when first starting out in the morning or when sitting for a long time and occasionally in reverse. Transmission shop is still trying to find that problem... I will also add that both the front differential and rear differential gave out during this period, I believe it was because of the shifting problems.. I now have more invested in the vehicle than it is worth!! 160k miles..
Welcome to the Club from a fellow Floridian.

I am sorry to here about these troubles. The transmission is the one thing that I keep my eye on most in this vehicle. What specifically gave out on the the differentials, i.e., were their metal fragments in the gears, busted seals, etc.?
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