1995 Camry CEL code 52

Tiny
PEGLEG95
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  • 1995 TOYOTA CAMRY
I have a 1995 Camry 2.2 automatic with 220,700 miles on it. The car is in great shape and I picked it up cheap for my 16 year old daughter. The guy I bought this car off of rebuilt the top end of the motor at 213,000 miles because the car had been overheated. It runs great but gets poor fuel economy. It also throws a check engine light once you start driving (not just running - you can rev the engine in park and there is no check engine). I flashed the codes and got a 52 from the check engine and a 63 from the O/D off light. I believe the transmission code 63 is "shift solenoid #2" and the CEL code 52 is "knock sensor". My question is: is it possible that the knock sensor really is bad? I always heard that knock sensors don't go bad and if you get a code you have a knock. I don't hear any knocking from the engine and since the light doesn't come on until the car is moving (usually about the first time it shifts to second) I believe it is the shift solenoid problem turning it on. The poor fuel economy leads me to believe that there may be a problem with something else and since that knock sensor code is present that might just be it. What do you think?


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Sunday, November 11th, 2007 AT 11:42 AM

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Tiny
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Hi there,

I would clear the codes and drive the car, re check for any new set codes. If the knock sensor is faulty there is a fair chance it will ping under heavy acceleration, at best it may not allow the timing to stabilize and poor economy will be an issue.

Mark (mhpautos)
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Sunday, November 11th, 2007 AT 8:12 PM
Tiny
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Thanks for the info. What is the best way to clear the codes? I am relatively certain that the transmission code is legit because the shift feels strange (surging around the shift point). I pulled the ECU fuse for about 15 minutes after doing a tranny service and cleaning the solenoids on the off chance that they were just clogged. It was after that that I flashed the knock sensor code.
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Monday, November 12th, 2007 AT 10:15 AM
Tiny
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Hi there,

To clear the engine codes remove the EFI fuse for 30 sec. With ignition off.

Mark (mhpautos)
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Monday, November 12th, 2007 AT 3:47 PM
Tiny
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I cleared the codes and took the car for a drive. Surprisingly the transmission code didn't come back but the knock sensor code did. The car also has a leak in the exhaust flex pipe and after a substantial drive I occasionally smell fuel when exiting the car. Could these be symptoms of a faulty knock sensor or is it possible that the sensor is picking up the exhaust leak as a knock? If that is the case, wouldn't a properly functioning sensor just retard the timing and not throw a check engine light?
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Wednesday, November 14th, 2007 AT 11:14 PM
Tiny
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Hi there,

The knock sensor won't pick up an exhaust leak, it picks up a change in the magnetic properties of a material depending on stress, this is called Magnetostriction, now it gets real technical after that so we won't go there. Basically the sensor detects knock or pinging and retards the timing to eliminate it. The fuel smell may not be associated at all but another fault worth looking into, as is the exhaust leak.

Mark (mhpautos)
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Wednesday, November 14th, 2007 AT 11:39 PM

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