Green Key Light on dash, codes P0685 and P0306?

Tiny
JGONZO2398
  • MEMBER
  • 2008 HONDA ACCORD
  • 3.5L
  • V6
  • 2WD
  • AUTOMATIC
  • 146,000 MILES
I recently had a check engine light come on for code P0685 (ECM Power Relay Circuit Open) and P0306 as it shows in my scanner app. The car drove home fine, but it did feel sluggish, like the engine could not haul as much as it normally would. When I checked under the hood, I noticed that the air intake hose had a significant rip where the steel vacuum line connected so I replaced that. Once I tried to start the car, it would only crank but not start and there was a green key light on my dashboard followed by a clicking sound. You can notice that the light behind the gear letters flashes alongside that clicking. I scanned the car again and no codes came up. I also checked multiple fuses such as the ACG fuse and the Fuel Pump fuse under the steering wheel which I read relate to the immobilizer, but they are both fine, not blown.
Tuesday, September 19th, 2023 AT 10:22 PM

2 Replies

Tiny
JGONZO2398
  • MEMBER
  • 362 POSTS
Update: I left the battery disconnected overnight and connected it this morning, but the car still only cranks but doesn’t start. However, the green key light is no longer staying on and that clicking sound is still ongoing. I removed the plastic trim from under the steering wheel and the noise seems to be coming from that internal area close to the left side of the steering wheel, as seen in the video. You can also hear the noise coming from the engine, and this is when the key is simply in the on position.
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Wednesday, September 20th, 2023 AT 6:27 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
Thanks for the videos, they help. in the first video that is a problem with the air intake boot, also can I ask if this is a hybrid? We should run the codes by doing a CAN scan.

You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

I would check all fuses and look at the battery ground to the engine block and to the body.

This guide can help:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Please go over these guides and get back to us.
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Thursday, September 21st, 2023 AT 10:37 AM

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