I'm pretty sure the VSS needs to be replaced based on the speedo symptoms but was waiting for cooler weather to replace. Today, with car warmed up, I was pulling away from a light and the car barely accelerated and had much trouble getting up to speed. It felt to me like a transmission related issue but wonder if it could be an ECU reaction to no VSS signal. The speedo is not working (most of the time) and D4 light flashes ontinuously. The CEL only comes on after driving about 20-30 minutes.
Any idea what could be causing the poor acceleration/driveability?
I appreciate any help,
Charlie

 

The check engine light (CEL) means the engine computer (ECU) detected a problem. The D4 light means the transmission computer (TCU) detected a problem. Both computers store a code to help you troubleshoot. All you need is a piece of wire or a thin paperclip to short the connector and get the codes.

For instructions see: dhost.info/accordinfo/howto/cel.html

You will count the check engine light flashes for the ECU codes, count the D4 light flashes for the TCU codes. When finished, post the codes on here, and tell us what codes came from the CEL, and the D4 light.

 

Thanks for the advice. Jumpered the connector and got CEL code 17 - VSS Sensor and TCU Code 4 - Possible Speed Sensor.
Having a little trouble identifying/finding the VSS but will search this site for prior posts.
Thanks

 

I found the underhood photo/diagram PAHonda posted earlier and will check VSS connections next.
Also, behind the glove box, I noticed the blue 2 pin diagnostic connector and the larger blue connector on same branch of wiring harness were both disconnected with no obvious place to plug them in. Is this normal or should one or both be connected to somewhere?
Thanks

 

No, they're not connected. There would have been a kind of rubber holder for them but it has no electrical connections.

 

Found good voltage (11.49) at yellow wire of VSS connector, reconnected then reset ECM and will see if symptoms & codes reappears before buying new VSS. Any details or suggestions on replacing VSS. It seems very hard to access even after removing rubber air intake.
Also, I found the blue plastic connector that holds the two test connectors in place under glovebox.

 

Speedometer is working fine and car is driving well. I got a CEL on way home from work - stopped and checked code and this time it was CEL Code 12 (EGR) and D4 was blinking 9 times (what does that mean?). I cleaned the intake ports about 1 year/6000 miles ago so doubt that is clogged again. Pulled backup fuse and went home and back to work - so far no issues-no lights.

 

Speedo and cruise working great & car is running well. After pulling backup fuse and resetting twice I keep getting a Check Engine Light with code 12. Any suggestions as to what I need to do now?
Thanks

 

The main page of that site has the 94 shop manual in pdf form broken into chapters. The EGR tests are in the fuel/emissions section. You can also download the entire manual from the spooner link in the online manuals thread in the main DIY section.

Check the connection (electrical and vacuum) on the EGR valve. Also you can follow the testing procedure on page 11-115.

 

I finally got time to check and found I had left the electrical connector to the EGR unplugged. Plugged it back in, removed the backup fuse to clear code and now everything is great underhood. Now if I just replace the rear driver's side door lock actuator everything will be working again!
And a special Thank You to PAhonda for all your excellent advice. This is a great resource for everyone.
Thanks,
Charlie