Strange Error Code Issue
12-08-14, 01:56 PM
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Strange Error Code Issue
My wife and I recently (3-4 months ago) purchased a used 2007 ES350 from a private seller. The guy seemed honest, and was selling because the depreciated value of the car no longer allowed for a tax write-off for his business (he purchased a new Audi A4).
Anyway, down to the nuts and bolts... The car had 113,000 miles when we bought it. At about 114k the check engine light came on. The error code was P0300, P0352, P0306, P0305, P0304, P0303, P0302, and P0301. Basically, misfire's on all 6 cylinders and a coil issue on coil B (cylinder 2).
I have a very experienced mechanic, who used to be a GM dealer mech, but now rent's out my grandpa's old shop in town. He suggested replacing plugs first. I had him do it. The light came back on, referencing Coil B/Misfires, once again. I went ahead and had him replace ONLY Coil B. All was well for a few miles. Then the light came back on. The light will come and go as it pleases (it will go off without clearing the codes with a code reader). He also replaced Coil B on warranty, took it out for a drive, and the light came back on. Sometimes we'll get 40-50 miles with the light off, other times, just driving it a mile and a half to get gas, it'll come on.
I just had it back to the shop today. He put his super sophisticated (he said he paid over 6k for it) on the car and drove it on 6 different trips. He started by clearing all codes. He then drove it, the light did come on. When he got it back to the shop, even though the code triggered, there were NO misfires logged on the computer. Neither one of us feel any misfires as we are driving, either. He and I are both 100% baffled by this issue.
Has anyone else had a similar issue? Any known fixes? He suspects it may be a software issue on the ECU. Is there a process to do a "re-learn" on the ECU?
TL/DR version: Error codes pointing to Coil B/Misfires. Replaced plugs. Replaced Coil B. Replaced Coil B with a warrantied part. Still getting error codes. Code reader showing 0 misfires. STUCK!
Any help would be MUCH appreciated!
Thanks!
Shane
Anyway, down to the nuts and bolts... The car had 113,000 miles when we bought it. At about 114k the check engine light came on. The error code was P0300, P0352, P0306, P0305, P0304, P0303, P0302, and P0301. Basically, misfire's on all 6 cylinders and a coil issue on coil B (cylinder 2).
I have a very experienced mechanic, who used to be a GM dealer mech, but now rent's out my grandpa's old shop in town. He suggested replacing plugs first. I had him do it. The light came back on, referencing Coil B/Misfires, once again. I went ahead and had him replace ONLY Coil B. All was well for a few miles. Then the light came back on. The light will come and go as it pleases (it will go off without clearing the codes with a code reader). He also replaced Coil B on warranty, took it out for a drive, and the light came back on. Sometimes we'll get 40-50 miles with the light off, other times, just driving it a mile and a half to get gas, it'll come on.
I just had it back to the shop today. He put his super sophisticated (he said he paid over 6k for it) on the car and drove it on 6 different trips. He started by clearing all codes. He then drove it, the light did come on. When he got it back to the shop, even though the code triggered, there were NO misfires logged on the computer. Neither one of us feel any misfires as we are driving, either. He and I are both 100% baffled by this issue.
Has anyone else had a similar issue? Any known fixes? He suspects it may be a software issue on the ECU. Is there a process to do a "re-learn" on the ECU?
TL/DR version: Error codes pointing to Coil B/Misfires. Replaced plugs. Replaced Coil B. Replaced Coil B with a warrantied part. Still getting error codes. Code reader showing 0 misfires. STUCK!
Any help would be MUCH appreciated!
Thanks!
Shane
12-10-14, 04:39 AM
#2
My wife and I recently (3-4 months ago) purchased a used 2007 ES350 from a private seller. The guy seemed honest, and was selling because the depreciated value of the car no longer allowed for a tax write-off for his business (he purchased a new Audi A4).
Anyway, down to the nuts and bolts... The car had 113,000 miles when we bought it. At about 114k the check engine light came on. The error code was P0300, P0352, P0306, P0305, P0304, P0303, P0302, and P0301. Basically, misfire's on all 6 cylinders and a coil issue on coil B (cylinder 2).
I have a very experienced mechanic, who used to be a GM dealer mech, but now rent's out my grandpa's old shop in town. He suggested replacing plugs first. I had him do it. The light came back on, referencing Coil B/Misfires, once again. I went ahead and had him replace ONLY Coil B. All was well for a few miles. Then the light came back on. The light will come and go as it pleases (it will go off without clearing the codes with a code reader). He also replaced Coil B on warranty, took it out for a drive, and the light came back on. Sometimes we'll get 40-50 miles with the light off, other times, just driving it a mile and a half to get gas, it'll come on.
I just had it back to the shop today. He put his super sophisticated (he said he paid over 6k for it) on the car and drove it on 6 different trips. He started by clearing all codes. He then drove it, the light did come on. When he got it back to the shop, even though the code triggered, there were NO misfires logged on the computer. Neither one of us feel any misfires as we are driving, either. He and I are both 100% baffled by this issue.
Has anyone else had a similar issue? Any known fixes? He suspects it may be a software issue on the ECU. Is there a process to do a "re-learn" on the ECU?
TL/DR version: Error codes pointing to Coil B/Misfires. Replaced plugs. Replaced Coil B. Replaced Coil B with a warrantied part. Still getting error codes. Code reader showing 0 misfires. STUCK!
Any help would be MUCH appreciated!
Thanks!
Shane
Anyway, down to the nuts and bolts... The car had 113,000 miles when we bought it. At about 114k the check engine light came on. The error code was P0300, P0352, P0306, P0305, P0304, P0303, P0302, and P0301. Basically, misfire's on all 6 cylinders and a coil issue on coil B (cylinder 2).
I have a very experienced mechanic, who used to be a GM dealer mech, but now rent's out my grandpa's old shop in town. He suggested replacing plugs first. I had him do it. The light came back on, referencing Coil B/Misfires, once again. I went ahead and had him replace ONLY Coil B. All was well for a few miles. Then the light came back on. The light will come and go as it pleases (it will go off without clearing the codes with a code reader). He also replaced Coil B on warranty, took it out for a drive, and the light came back on. Sometimes we'll get 40-50 miles with the light off, other times, just driving it a mile and a half to get gas, it'll come on.
I just had it back to the shop today. He put his super sophisticated (he said he paid over 6k for it) on the car and drove it on 6 different trips. He started by clearing all codes. He then drove it, the light did come on. When he got it back to the shop, even though the code triggered, there were NO misfires logged on the computer. Neither one of us feel any misfires as we are driving, either. He and I are both 100% baffled by this issue.
Has anyone else had a similar issue? Any known fixes? He suspects it may be a software issue on the ECU. Is there a process to do a "re-learn" on the ECU?
TL/DR version: Error codes pointing to Coil B/Misfires. Replaced plugs. Replaced Coil B. Replaced Coil B with a warrantied part. Still getting error codes. Code reader showing 0 misfires. STUCK!
Any help would be MUCH appreciated!
Thanks!
Shane
Did he check if the coil is getting ground and power? The coil is only part of the circuit - the wiring has to be checked and if it is ok, then the ECU may be suspect as well. Before he ever replaced that coil, he should have swapped it with another cylinders coil and see if the problem followed the coil denoting a failed coil, or if it stayed at that cylinder, denoting wiring / potential ecu failure.
12-11-14, 10:43 AM
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Toyota ECU's don't report individual cylinder misfire counts like he is used to seeing, at least not with a non-toyota diagnostic tool.
Did he check if the coil is getting ground and power? The coil is only part of the circuit - the wiring has to be checked and if it is ok, then the ECU may be suspect as well. Before he ever replaced that coil, he should have swapped it with another cylinders coil and see if the problem followed the coil denoting a failed coil, or if it stayed at that cylinder, denoting wiring / potential ecu failure.
Did he check if the coil is getting ground and power? The coil is only part of the circuit - the wiring has to be checked and if it is ok, then the ECU may be suspect as well. Before he ever replaced that coil, he should have swapped it with another cylinders coil and see if the problem followed the coil denoting a failed coil, or if it stayed at that cylinder, denoting wiring / potential ecu failure.
He did check the wiring, yes. When he replaced the coil the second time with the warrantied part, he did swap the coil and the wiring -- he got the same result after the swap (errors about cyl 2). I assume this means there is an issue with the ECU, correct? This is where I lose competency... Is the ECU a replaceable part? I'm fairly certain that there is a "re-learn" or "re-program" process for an ECU (is that correct)? If not, what are my next steps? I'm not really interested in paying Lexus of Madison $130/hr to diagnose an issue just to tell me it either A. cannot be fixed or B. is going to cost thousands of dollars to fix.
Thoughts?
12-11-14, 10:51 AM
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In addition to my previous post... I just stumbled onto this post:
https://www.clublexus.com/forums/ls4...capacitor.html
I do experience some of the issues listed there...
-Weird shifting problems. Sometimes it'll shift and then accelerate slightly when shifting down coming to a stop.
-throwing out random fault codes -- Obviously this is what this post is about.
https://www.clublexus.com/forums/ls4...capacitor.html
I do experience some of the issues listed there...
-Weird shifting problems. Sometimes it'll shift and then accelerate slightly when shifting down coming to a stop.
-throwing out random fault codes -- Obviously this is what this post is about.
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