# 2023 Toyota Sienna - Harness code **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** toyota\ **Created:** [August 20, 2022, 4:25pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919 "2022-08-20T16:25:35Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![ulu18g](https://avatars.discourse-cdn.com/v4/letter/u/f14d63/32.png) [@ulu18g](https://community.cartalk.com/u/ulu18g)\ **Post date:** [August 20, 2022, 4:25pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/1 "2022-08-20T16:25:35Z")
I replaced my knock sensors recently. Check engine light came off for a week but then returned. OBD says harness wires to knock sensor may need to be replaced. Could I get by without replacing harness inasmuch as I’ve replaced the knock sensors? Or am I stuck having to replace harness? ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [August 20, 2022, 6:09pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/2 "2022-08-20T18:09:13Z")
WOW, so much for Toyota alleged quality, 2023 required knock sensor replacement… ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [August 20, 2022, 7:29pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/3 "2022-08-20T19:29:41Z")
I suspect that you have an open circuit fault. If you want the check engine light off and the engine to operate properly, the wiring problem will need to be repaired. Because of the amount of labor involved, I usually replaced the knock sensor harness or connectors when replacing knock sensors. This vehicle is ten years old, 2023 is the default in the scroll down when a model year is not selected. ---
**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\ **Post date:** [August 20, 2022, 7:41pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/4 "2022-08-20T19:41:19Z")
If this is really a 2023, you should not replace anything. just bring it to the dealer under the warranty. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [August 20, 2022, 8:35pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/5 "2022-08-20T20:35:49Z")
The knock sensor signal is how the drivetrain computer determines if the engine timing is too far advanced. If it is too far advanced, that will damage the engine parts; so if the knock sensor signal isn’t reaching the computer, and the computer has determined it’s b/c the wire between sensor and computer isn’t connected, computer has no choice but to set ignition timing retarded enough engine won’t be damaged. But that will significantly reduce your available engine power. That’s why for the engine to work properly, the knock sensor needs to reach the computer. This is sort of like attending a rock concert, and discovering you can’t hear the music. Is it b/c the musicians’ instruments are faulty? Or b/c they are only pretending to play? They are playing, but their guitar’s aren’t connected to the sound amplifier input? Signal is reaching sound amplifier input, but sound amplifier isn’t powered up? Speaker’s disconnected? Well you get the idea, lots of possibilities. By analogy you attempted to solve the problem by replacing the instruments, and discovered you still can’t hear the sound. So now you have to test each of those other possibilities one by one. Either that or just replace all the other stuff, which would be sort of equivalent to replacing the car’s wiring harness component for the knock sensors. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [August 20, 2022, 8:53pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/6 "2022-08-20T20:53:41Z")
> [@Nevada\_545](#): > > This vehicle is ten years old Just curious , how did you find the vehicle age ? ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [August 20, 2022, 9:03pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/7 "2022-08-20T21:03:16Z")
Knock sensor problems generally occur after ten years, I’m not fooled by the title. ---
**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\ **Post date:** [August 20, 2022, 9:24pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/8 "2022-08-20T21:24:14Z")
And that’s why you get paid the big bucks. 🤣 ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [August 20, 2022, 9:33pm UTC](https://community.cartalk.com/t/2023-toyota-sienna-harness-code/185919/9 "2022-08-20T21:33:25Z")
Nevada is keeping all of us honest … lol …