I have a 94 Accord with a VTEC engine. I have D4 blinking as well as check engine light illuminated. I checked the codes by jumping the pins of the connector under the glove compartment. Had Code 4 for Transmission and Code 17 for Check Engine. Both Codes indicate Vehicle Speed Sensor. I replaced the Vehicle Speed Sensor. I still get a flashing D4 as well as the Flashing Check Engine light when I start the car. What does this indicate? A wiring problem to the VSS? How would I further diagnose the problem?

 

Most likely a wiring problem to the VSS.
VSS - Vehicle Speed Sensor Troubleshoot, Repair, Replace - How To.

 

I am trying to follow the troubleshooting in the link Mad Mike provided. I am not strong with electronics so this question may be elementary, but......

There is 12V on middle terminal at the connector and there is ground on the black terminal and 5V on the 3rd terminal at the connector when I turn on the ignition.

The second step says to raise the car and see if there are 5V pulses at the speed sensor. How can I test the voltage at the speed sensor if the connector is plugged in?

 

Back probe the connector.

 

I tried to back probe but the back side of my connector seems pretty tight and the probe did not indicate any Voltage readings. (my wife got a kick out of me telling my son we were going to probe the back side)

So I opted for a road test. First I left the VSS sensor disconnected. The CEL and flashing D4 illuminated. Also the Cruise Control does not work when the VSS is unplugged.

I stopped and plugged in the VSS connector and the CEL and D4 did not illuminate and the Cruise Control works. Although the Speedo still does not.

Part of my problem is solved but the Speedo still does not work.

Also, I should mention that the gauges (temp, fuel, tach, speed) on my main instrument panel do not illuminate when I turn my lights on. Neither does the temperature control **** or the Cool/Heat setting ****.

The other lights such as BRAKE, Battery Icon, OIL Dummy light, ABS, SBS, Cruise Control, etc do work when the lights are on or off.

Ideas?

 

Get another vss off ebay or amazon for $15 and swap it in.

 

Many of the 5th gens had an issue with the PCB on the speedo - I'll assume the odo and trip are not working as well.

For the lights. check the fuses, also test the dash dimmer.