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Code 52 only when cold?

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Old 03-22-2013, 11:59 AM
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Code 52 only when cold?

Hey guys, i'm wondering if anyone has had an issue like this. The code 52 for the knock sensor is very common. As i understand it, the knock sensor uses a piezo element to monitor engine vibrations and produces voltage accordingly. Under knocking conditions, the ecu detects that specific voltage and retards timing to avoid knock. If the ECU recieves no signal from the knock sensor over about 1200 RPM, code 52 is triggered. The most common causes of code 52 are due to bad wiring, whether it be in the connector, pigtail, shorts, or splices.

I've been getting a code 52 the first time i drive it every day. ONLY when the engine is cold. Starts great, runs great, but if i get it above 1200 RPM while cold, BAM! Code 52. As soon as it warms up, i turn the key off and then back on, and the check engine light never comes back.

"Well great, I'll just rewire it!" As recommended in many writeups, i removed and cut off the connector, depinned the connector, soldered on some shielded wire, and ran it straight back to wire going into the ECU, grounding the wire shielding near the ECU. NO change. Seems odd to me. Seems like some kind of thermal failure in a borderline sensor. I've done some research and it seems like folks can't agree on the durability of toyota knock sensors. People on here swear they NEVER go bad, that the problem is ALWAYS the wiring. I'm confident in my rewiring job that it's not the problem. Anybody else had a similar problem? I'd rather not replace the sensor unless i'm sure it's bad, seeing how i could almost get a rear locker for the same price.
Old 03-22-2013, 12:52 PM
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If you've already done the wiring and are certain it's good, the only things left are a new sensor or perhaps making sure it's firmly attached but really even loose I'd expect it to send some signal.
Old 03-23-2013, 08:08 AM
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So i ran across this thread the other day, does anyone else have experiences with this kit? I've been emailing back and forth with the company that makes it and although it's made for a different motor, they feel it should work. I've also discovered that cavaliers have the same thread size, and similar displacement, so i've been considering that as well.
Old 12-06-2023, 04:27 AM
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Originally Posted by Inferno451
Hey guys, i'm wondering if anyone has had an issue like this. The code 52 for the knock sensor is very common. As i understand it, the knock sensor uses a piezo element to monitor engine vibrations and produces voltage accordingly. Under knocking conditions, the ecu detects that specific voltage and retards timing to avoid knock. If the ECU recieves no signal from the knock sensor over about 1200 RPM, code 52 is triggered. The most common causes of code 52 are due to bad wiring, whether it be in the connector, pigtail, shorts, or splices.

I've been getting a code 52 the first time i drive it every day. ONLY when the engine is cold. Starts great, runs great, but if i get it above 1200 RPM while cold, BAM! Code 52. As soon as it warms up, i turn the key off and then back on, and the check engine light never comes back.

"Well great, I'll just rewire it!" As recommended in many writeups, i removed and cut off the connector, depinned the connector, soldered on some shielded wire, and ran it straight back to wire going into the ECU, grounding the wire shielding near the ECU. NO change. Seems odd to me. Seems like some kind of thermal failure in a borderline sensor. I've done some research and it seems like folks can't agree on the durability of toyota knock sensors. People on here swear they NEVER go bad, that the problem is ALWAYS the wiring. I'm confident in my rewiring job that it's not the problem. Anybody else had a similar problem? I'd rather not replace the sensor unless i'm sure it's bad, seeing how i could almost get a rear locker for the same price.
I know this is an old thread.. but im having the same issues. Did you ever pin point the problem?
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