LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

MAF circuit malfunction

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Old 10-04-13, 05:13 PM
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Hank357
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Default MAF circuit malfunction

I coded my 97 LS400 and got the P0100 and P0110 which are MAF circuit malfunction and IAT circuit malfunction. I replaced the mass air flow meter and when I rescanned for codes the same codes came up. What else could cause this problem. I'm thinking the ECM is bad. Please help.
Old 10-04-13, 05:31 PM
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LScowboyLS
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the ECU may well be bad, as your year is afflicted with the epidemic of failing ECU capacitors, can you open it up and check for leakage or perform Yamae's ripple test?

In any event, you should think about doing the ECU capacitors regardless, because they will fail and when the do, they can quickly ruin the main lower circuit board of the ECU, then you have to get a junkyard ECU and have the capacitors done!

a capacitor is like a tiny battery, and we all know that a battery won't last 17 years in a car, electrolytic capacitors are good for about 12 years, depending on temperature, humidity, and amount of time the car has been parked for extended periods.
Old 10-04-13, 05:39 PM
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cobalt91
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Don't forget to look for lose ducting or areas were unmetered air can get in.
Old 10-04-13, 05:52 PM
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LScowboyLS
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Originally Posted by cobalt91
Don't forget to look for lose ducting or areas were unmetered air can get in.
the is a great point, I have more than once found areas were the intake tube is starting to separate from old age and doesn't fit airtight, although this wouldn't tend to cause the particular codes you have, but it certainly would let undesirable particles into the engine
Old 10-04-13, 06:02 PM
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deanshark
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Originally Posted by Hank357
I coded my 97 LS400 and got the P0100 and P0110 which are MAF circuit malfunction and IAT circuit malfunction. I replaced the mass air flow meter and when I rescanned for codes the same codes came up. What else could cause this problem. I'm thinking the ECM is bad. Please help.
Did you disconnect the battery or pull the ECU fuse to clear the codes? If not, that could be why you have the same codes coming up.
Old 10-04-13, 06:18 PM
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LScowboyLS
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Originally Posted by deanshark
Did you disconnect the battery or pull the ECU fuse to clear the codes? If not, that could be why you have the same codes coming up.
another great point, you guys are way smarter than me tonight!
Old 10-04-13, 07:16 PM
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Yamae
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There are great many people over here and you are helping people next to next.
I like that.
Old 10-04-13, 07:21 PM
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cobalt91
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How does it run?
Old 10-04-13, 08:56 PM
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Hank357
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The car runs like a sewing machine. I'm not losing any power and there's no hesitation.
Old 10-04-13, 09:02 PM
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Hank357
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I am not experiencing any of symptoms listed for a failing ECU capacitors.
Old 10-04-13, 09:55 PM
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Hank357
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Originally Posted by cobalt91
How does it run?
The car runs like a sewing machine.
Old 10-04-13, 09:58 PM
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LScowboyLS
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if the ECU capacitors were bad, the car will not be running flawlessly!
Old 10-05-13, 01:21 AM
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cobalt91
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I would check the connections on the sensors. Might be a loose wire.
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