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I received your idea on taking the board out and solder any loose terminals and I would do that but the lines coming out of the aluminum block keep the actuator from coming all way off. There is not enough space. I can send pics to clarify if needed.
Thanks for the thought but Lexus did extend the coverage up to Dec.2017. This vehicle missed that window, went bad on me and I will get it fixed in the future. Can't find a soul out there that knows any short cuts for this fix except to purchase a $300 Techstream brake bleeding software that may or maynot work for me. If any ideas certainty pass them on, I would appreciate it.
Thanks for the thought but Lexus did extend the coverage up to Dec.2017. This vehicle missed that window, went bad on me and I will get it fixed in the future. Can't find a soul out there that knows any short cuts for this fix except to purchase a $300 Techstream brake bleeding software that may or maynot work for me. If any ideas certainty pass them on, I would appreciate it.
Dano3899-C1391
4
I thought I bought the techstream on ebay for around 35.00,...
I also am having this issue,..I'll include a picture of the techstream screen shot incase anyone knows which variables with voltage are the ones to check out.
I've read the above list of system checks with the voltage of the accumulator but did'nt see it by that specific name on the image.
Anyone care to look at the image and see if my voltages are correct?
Looks like your on it! Everyone on this end may be looking at the wrong item. Looking at your finding, it looks like the Accumulator. If I understand this right, this is underneath the vehicle mid section. Is that correct?
Dano3899-C1391
Looks like your on it! Everyone on this end may be looking at the wrong item. Looking at your finding, it looks like the Accumulator. If I understand this right, this is underneath the vehicle mid section. Is that correct?
Dano3899-C1391
Pay no attention to my "cursor" position in the image,.. Its actually the CELL below that in the "accumulator sensor" row that I'm assuming is the one to look at.
According to yyymmm post above I thought he was saying that "If your brake actuator has the normal voltage range of 3.2-4.0V, then, your brake skip control ECU is bad and you need to replace it, not the brake actuator."
I thought the usual cause of the accumulator failure was an internal leak, loss of pressure and the need for the pump to try to compensate? I find this system to be confusing simply because it's not like most systems (typical master cylinder and ABS module). This system uses a different master cylinder.
As far as bleeding goes, I believe their are scan tools that can handle this task without tech stream, but honestly those tools are more expensive than having tech stream. Lol. But I imagine some Indy shops can bleed these cars.
I thought the usual cause of the accumulator failure was an internal leak, loss of pressure and the need for the pump to try to compensate? I find this system to be confusing simply because it's not like most systems (typical master cylinder and ABS module). This system uses a different master cylinder.
As far as bleeding goes, I believe their are scan tools that can handle this task without tech stream, but honestly those tools are more expensive than having tech stream. Lol. But I imagine some Indy shops can bleed these cars.
Thanks for your last comment. I will ask Lexus about the ECU before replacing the actuator. Thanks,
Dano3899 - C1391, C0210 fault codes.
OK, this is what is known at this time concerning my 2007, 460 ABS problem. Took the car into Lexus dealer and had installed a new actuator. cost $2,260. took the old actuator home, took it apart and discovered one of the fluid holes stopped up with some kind of compound like hardened grease. Pic shows obstruction in one of the 7 holes where fluid is present. Difficult to deny that this should not be there. This pic and more sent to the Lexus dealer. I really dont expect Lexus to acknowledge this finding, but it is what it is. Thanks from Dano3899.
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Before I answer your question, I have a small request for you. Please keep us posted and share with us how you eventually solve the problem. I answered quite a few 1-posting questions. After I took the time to provide my recommendations, the person who posted the question never came back to share if the problem was solved and how it was resolved. Sharing information on this forum will help others who may have the same problem in the future.
-Yes, you can do a lot at home, if you are willing to do it, including fully fixing the problem on your own. Error code C1391 (and C1396) suggests three possible problems: (1) leak in brake hoses between the brake actuator and brake caliper (i.e., not an actuator problem), (2) a bad brake skip control ECU (i.e., again, not an actuator problem), and (3) a bad brake actuator.
-The first step is to check if there is any external leaks on brake hoses. If there is any leak on a brake hose, replace the broken hose and problem is solved.
-If there is no leaks on brake hoses, if you are handy and have Techstream, you can check the brake actuator pressure voltage. A functional brake actuator should have a voltage range of 3.2-4.0V. You do this test with the engine ignition at ON position (but not actually starting the engine). If the brake actuator pressure is not in the normal range, you can do a full brake bleeding with Techstream per factory service procedure and see if the full brake bleeding fix the problem. In some cases, full brake bleeding fixes the problem. If a full bleeding doesn't fix the problem, you will need to replace the brake actuator.
-If your brake actuator has the normal voltage range of 3.2-4.0V, then, your brake skip control ECU is bad and you need to replace it, not the brake actuator.
Hope that this is helpful. Again, please keep us posted about the outcomes.
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Morning yyymmm31,
Have you read my last blog and findings on LS460 actuator problem. let me know when you do.
thanks.
Hi Dano,
While you're waiting for yyymmm to get back to you, I have a question.
How many miles on your car, and do you know, or think that the brakes have ever been bled prior to this problem? The white substance you found looks to me like it might be water contamination. They say that brake fluid is a desiccant and picks up water over the years; and is the reason they recommend regular fluid flushes. I'm wondering if regular brake flushes are needed to save the system.
Thanks!
Thanks for your reply. This car had 128k when I bought it. Problem came up after 2 days of driving and using the "HOLD" feature at a red light. I can only say the original owner religiously took this vehicle in during the contract maintenance period. One of the reasons I purchased this 1 owner. All I have from the carfax is "brakes checked at 22k mile mark". After that he goes to a different source for service. So what your asking could be a yes, that the brake fluid should be replaced by the manual. These cars are very different than the old master calendar setup. Makes me wonder why I never hear of F's & C's having this problem.
thanks from Dano3899
OK, this is what is known at this time concerning my 2007, 460 ABS problem. Took the car into Lexus dealer and had installed a new actuator. cost $2,260. took the old actuator home, took it apart and discovered one of the fluid holes stopped up with some kind of compound like hardened grease.
Pic shows obstruction in one of the 7 holes where fluid is present. Difficult to deny that this should not be there. This pic and more sent to the Lexus dealer. I really dont expect Lexus to acknowledge this finding, but it is what it is. Thanks from Dano3899.
Hi, Dano3899. I've been busy with holiday travel and other work/family chores and haven't read the forum postings closely for a while. Thank you for sharing your experience in diagnosing code C1391 and solving your brake problem. I consider the brake actuator a non-repairable item mainly because it is a mission-critical brake system component. When I determined a brake actuator was bad, my usual approach was to replace the actuator as a whole. I have not taken apart an actuator and attempted to repair it (although I have taken apart starters and alternators and repaired them by replacing worn parts). So, you are ahead of me in this regard, and I can't offer comment or suggestions if the blocked fluid hole inside the actuator is the cause of the actuator's malfunction. One thing is for sure from my experience: The fluid of the brake system of LS460 (and other Lexus cars) needs to be replaced per the service schedule and per Lexus service procedure, in order to maintain proper braking function. I've seen sticky and noisy brake caliber pistons and other abnormal brake behaviors due to old brake fluid and were easily fixed by properly replacing the brake fluid per Lexus service procedure.
Enjoy your LS460.
