90 Civic STD with D15B1 with no MOD except 4-1 header and cat back.
CEL comes on when decelerating and remains on during the drive.
Upon restart of engine, there is no CEL till drive the car to decelerate.
Checked code on ECU and get short 17 blinks. It is for VSS.

Speedometer does not work so I am guessing the CEL is for "VSS INOP". Otherwise the car drives nice.

I thought VSS is for auto transmission and not for manual transmission.

Can some one shed the light on this? Thank you.

 

You will get that because the speedometer does not work. There is a sensor in the speedometer head in the cluster which drives pulses to the ECU. Thus if the cable is broken (before 1992 the Civic speedometers were mechanical with a flexible shaft cable to the transmission) the ECU gets no signal from the sensor. I'm not sure exactly what the ECU does with the signal from the VSS, but it will complain if it doesn't get it. When it sees the engine spinning above idle speed with zero throttle for a prolonged period, it knows that the car must be moving, that is when it detects the VSS malfunction.

 

Wow, thank you for quick answer.

It must have something to do with speedo, I thought, but wasn't sure about it. The car has been doing this for a while, my better half tells me. Possibly the speedo stopped working late last year. I couldn't link VSS and manual transmission in my head.

I checked speedo cable and it is securely on on the transmission. I haven't checked on cluster side.

When I did engine and transmission R/R last spring, I had loosened a bolt where speedo cable attached on the transmission in an attempt to disconnect the cable. Later, my son informed me I shouldn't have done that for disconnecting it. He was checking the Haynes. He said that doing so will dislodge something inside the transmission making speedo INOP. The car have a few thousand miles since then, I thought I got away with that.

I checked the manual now but can not find what he was finding back then.

Now, if it was indeed something became loose that making speedo INOP, do you think it is possible to fish it up? I am thinking this "it" will be a drive gear for speedo cable.

Oh, in February, my son accidentally drained transmission fluid/oil by mistake, thinking he is draining engine oil. I checked the drained oil and found no metal flakes. So I am thinking nothing is chewed up inside,,,,. I hope.

 

Usually the center core part of the cable breaks, where it bends to go through the firewall. You can find this by disconnecting the cable at the transmission and pulling the core out. Pull up the rubber boot and pull the wire clip out of the side of the fitting, now the cable will come out. Pull the center part out and inspect the end. It should end in a nice square part to mate with the speedo. (You need to take the other end off of the speedo to get the other broken part out.)

 

Before I read the post, MK, I disconnected cable from transmission side. I pulled the shaft but it didn't come out as easily as I anticipated. So I didn't force it.

Took a hand drill and clamped the shaft, turned the shaft in the direction I think it is for normal direction. My neighbor was in the car looking at the speedo needle. He can hear a sound from the cluster but no needle movement. I reversed the direction of rotation but the result was the same, no movement.

Next time I have chance, I will pull the shaft harder so it will come out. I can do this now knowing the construction of the speedo cable is the same as a tach cable for Cessnas and Pipers, which I work on all the time.

 

It should slide right out.

 

Had to use a pair of priers to pull it out. It seems like a strand of the shaft was mangled inside the casing. I am searching for part number so I can place order but no avail so far.

Majestic Honda is the site I use to locate the part number and purchase. Does anyone know the part number for speedo cable?

 

NAPA AUTO has this cable listed for $23, P/N BK 6151698.

Called the store near me and it will be there in 6 hours time.

 

Got the cable yesterday, installed today. The cable was made in Japan, possibly OEM.
Drove the car just enough to know the speedometer is working.
I'll go for a test drive in about two hours time and see if CEL would come on this time.

Oh, I followed DIY for cable replacement found on this forum. I had to remove cluster cover due to limited working room. My hands are smaller than most people I know but I just couldn't gain access to the back of speedometer.

 

Went out for errands, drove for 4 miles and there no CEL!!

When I was out to pick up the new cable yesterday, I learned the way to fool ECU even without Speedometer not working. Before stopping for a light or sign, I press on clutch to disengage and the CEL does not come on. It proves that the ECU is looking for RPM and MAP among other things to control the engine, I guess.