I have an 09 odyssey 3.5 and it has this 83 ecm reltion failure code and wont go over 3 grand on the tach.... whats your suggestion?

https://www.engine-codes.com/p1698_jeep.html

This will help you understand.

The Immobilizer needs to be reset to the vehicle so the ECM and BCM recognize it.

https://www.google.com/search?q=2006+honda+odyssey+reset+immobilizer

..

Thinking the ecm. Any suggestions? Yeah , take it to a qualified repair shop .

P0685 DODGE - Auto Shutdown Relay Control Circuit Failure
Possible causes - Faulty Engine Control Module (ECM) power relay
- ECM power relay harness is open or shorted
- ECM power relay circuit poor electrical connection
- Faulty (ECM
Possible symptoms:
Engine Light ON (or Service Engine Soon Warning Light) P0685 Dodge Description: Short or open in Auto Shutdown (ASD) relay circuit, this relay is under the hood in the relay center.

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Apr 7, 2008 - 8 posts - ‎2 authors 12 No tach signal to ECM - No Distributor Reference Pulses{4} ... solenoid circuit failure - 1987 and 1995 Amigo/Pick-up, 1989 to 1994 V6 models ... {9}-Amigo, Pickup,Rodeo & Trooper w/2.6L engine & 1988-91 Impulse.

This is an ECM failure code, probably will require a new computer.

This is an SRS code. Go to the Honda owners sight an enter your VIN in recalls. it will show you any on your Odyssey.

sounds like a tcc issue in the transmission. some times it can be fixed with an ecm flash. often it is a bad tcc solenoid inside the trans. valve body.

code p1298 refers to electrical load sensor--circuit/voltage high===causes wiring--under hood fuse box/relay plate--electrical load sensor--ECM programming---ECM

I would suggest taking it to a Honda service centre to have it checked out asap.

Sounds like your transmission light is going out. When the TC light comes on thats your first warning that something is wrong. This happened to us on our 2001 Odyssey in 2007 and Honda replaced the transmission under the 7 year 100000 mile warranty.