2008 RX 350 Trans problems after battery and alternator replacement
#1
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
2008 Lexus RX350. 120k. The vehicle died while driving after low battery light came on. Mechanic changed the alternator and battery.
On the way home, the trans started jumping out of gear, rpms revved high and dropped in gear.
Now it shifts erratically, slips, can't find gears.
How could replacing the battery and alternator lead to this?
Codes then came on P0776 Pressure Control Solenoid B Performance/Stuck off
P0741 Torque Converter Clutch Circuit Performance Stuck Off
Pretty sure the codes came on as a result of the erratic shifting and are not the actual problem.
On the way home, the trans started jumping out of gear, rpms revved high and dropped in gear.
Now it shifts erratically, slips, can't find gears.
How could replacing the battery and alternator lead to this?
Codes then came on P0776 Pressure Control Solenoid B Performance/Stuck off
P0741 Torque Converter Clutch Circuit Performance Stuck Off
Pretty sure the codes came on as a result of the erratic shifting and are not the actual problem.
#2
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
2008 Lexus RX350. 120k. The vehicle died while driving after low battery light came on. Mechanic changed the alternator and battery.
On the way home, the trans started jumping out of gear, rpms revved high and dropped in gear.
Now it shifts erratically, slips, can't find gears.
How could replacing the battery and alternator lead to this?
Codes then came on P0776 Pressure Control Solenoid B Performance/Stuck off
P0741 Torque Converter Clutch Circuit Performance Stuck Off
Pretty sure the codes came on as a result of the erratic shifting and are not the actual problem.
On the way home, the trans started jumping out of gear, rpms revved high and dropped in gear.
Now it shifts erratically, slips, can't find gears.
How could replacing the battery and alternator lead to this?
Codes then came on P0776 Pressure Control Solenoid B Performance/Stuck off
P0741 Torque Converter Clutch Circuit Performance Stuck Off
Pretty sure the codes came on as a result of the erratic shifting and are not the actual problem.
Last edited by Leeper; Yesterday at 03:17 PM.
#4
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Could be that a ground wire was left unhooked somewhere. My 2002 Highlander had similar behaviours after a valve cover gasket change, I let one of the small 10mm ground terminals unhooked. Was so bad I thought my trans was done for
The following 2 users liked this post by MattRX:
Margate330 (Today),
Oro (Yesterday)
#5
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
no, not heard of issues with their ECM's or TCM's, occasionally have heard of tranny issues but most are the result of not changing the fluid regularly and at 120K yours is overdue for fluid and filter change. Several people have said their cars felt odd until it releearned their habits once again.
#6
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I changed the fluid and filter to rule that out. I think it is electrical somehow.
I pulled the battery and did not see any ground wires laying loose. I'll check around the alternator.
I think this is more than a relearn.
I pulled the battery and did not see any ground wires laying loose. I'll check around the alternator.
I think this is more than a relearn.
#7
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I didn't find any issues with the wiring. Maybe I'll try a junk yard ECU.
I put a new valve body, trans filter and 3x trans fluid change with WS fluid.
Fluid was black, probably original. Not metal on magnets.
This all made no improvement.
I still have a hard time believing that the trans went immediately after having the battery and alternator installed.
I am still thinking it is electrical.
I put a new valve body, trans filter and 3x trans fluid change with WS fluid.
Fluid was black, probably original. Not metal on magnets.
This all made no improvement.
I still have a hard time believing that the trans went immediately after having the battery and alternator installed.
I am still thinking it is electrical.
Trending Topics
#8
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I didn't find any issues with the wiring. Maybe I'll try a junk yard ECU.
I put a new valve body, trans filter and 3x trans fluid change with WS fluid.
Fluid was black, probably original. Not metal on magnets.
This all made no improvement.
I still have a hard time believing that the trans went immediately after having the battery and alternator installed.
I am still thinking it is electrical.
I put a new valve body, trans filter and 3x trans fluid change with WS fluid.
Fluid was black, probably original. Not metal on magnets.
This all made no improvement.
I still have a hard time believing that the trans went immediately after having the battery and alternator installed.
I am still thinking it is electrical.
The following users liked this post:
Margate330 (Today)
#9
Lexus Test Driver
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Me either.
Of course anything is possible, like one in million chance on the day your alternator went out, transmission dies.
It doesn't add up. Lol
I will hazard a guess the alternator failure was a side effect
Like posted above, make absolutely sure your frame grounds and engine grounds are legit.
(1): What is the engine running voltage measured at the battery terminals?
(2): what is the engine running voltage with red probe of the meter on positive battery terminal and the black probe on the valve cover?
(3): what is the engine running voltage with red probe on the positive battery terminal and the black probe on a metal chassis ground? Can use anything unpainted metal on the chassis.
Of course anything is possible, like one in million chance on the day your alternator went out, transmission dies.
It doesn't add up. Lol
I will hazard a guess the alternator failure was a side effect
Like posted above, make absolutely sure your frame grounds and engine grounds are legit.
(1): What is the engine running voltage measured at the battery terminals?
(2): what is the engine running voltage with red probe of the meter on positive battery terminal and the black probe on the valve cover?
(3): what is the engine running voltage with red probe on the positive battery terminal and the black probe on a metal chassis ground? Can use anything unpainted metal on the chassis.
The following users liked this post:
Margate330 (Today)
#11
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Ok, I agree ECM, TCM probably not this issue as I have seen almost zero failures with them.
I checked the ground wire on top of the trans for voltage, also 14.0.
Who's next? Throw out some ideas.
Lets fix this together, LOL.
I checked the ground wire on top of the trans for voltage, also 14.0.
Who's next? Throw out some ideas.
Lets fix this together, LOL.
Thread
Thread Starter
Forum
Replies
Last Post
Peco
ES - 1st to 4th Gen (1990-2006)
16
07-02-22 10:25 AM