How do I replace the speedometer?

[otacon122]

I am getting TCU Error Code 4 - No signal from speedometer. How do I go about replacing the speedometer and what size speedometer gauge do I need?

[HenRoc]

Quick look up on that Code 4 reveals that the VSS is bad. You don't replace the Speedometer rather you replace the VSS.

The VSS is located on the transmission close to the fire wall and has a 3 pin connector relatively easy to spot.

To remove it you need to take out the two 10 mm bolts located on the VSS it self.

[otacon122]

Quick look up on that Code 4 reveals that the VSS is bad. You don't replace the Speedometer rather you replace the VSS.

The VSS is located on the transmission close to the fire wall and has a 3 pin connector relatively easy to spot.

To remove it you need to take out the two 10 mm bolts located on the VSS it self.

I checked with a speedometer repair place, and they said there's no way to tell what the problem is without actually looking. They said it could be the cluster, it could be the VSS, or it could be the wiring. I am also getting TCU codes 14 and 15, and it makes sense to me that the line pressure solenoid and kickdown switch would be tied into what the speedometer or VSS are saying.

[psawall]

No, it's your VSS. Oddly enough, I'm replacing mine this weekend because it's shot too! It works for about 5-10 minutes and then goes out. I get ECU and TCU errors on my automatic, not sure if you're getting the same. You can pick up a new sensor for pretty cheap on ebay.

[HenRoc]

I checked with a speedometer repair place, and they said there's no way to tell what the problem is without actually looking. They said it could be the cluster, it could be the VSS, or it could be the wiring. I am also getting TCU codes 14 and 15, and it makes sense to me that the line pressure solenoid and kickdown switch would be tied into what the speedometer or VSS are saying.

Code 15 is for the main shaft speed sensor

Code 14 is for FAS I forgot what the acronym stands for but Im literally reading the trouble shooting flow chart for you. Its a BRN/WHT wire between the ECM and TCU..but I highly doubt you have a short.

More than likely you have a faulty main shaft speed sensor..which in turn would cause the speedometer not to operate and Codes 14 and 15 to come on.

[otacon122]

Could I replace the VSS myself if I have no prior mechanical knowledge?

[HenRoc]

Could I replace the VSS myself if I have no prior mechanical knowledge?

Yes. Its very easy to replace. Get yourself a Helms manual I think retail is $60.

Get one for a 91 Accord though..since there were some slight changes mid year of the 4th gen.

[otacon122]

Yes. Its very easy to replace. Get yourself a Helms manual I think retail is $60.

Get one for a 91 Accord though..since there were some slight changes mid year of the 4th gen.

After checking the manual, I see there are three speed sensors on the car. The main shaft sensor, the counter shaft sensor, then that big speed pulse device thing that sits on top of the transmission near the differential housing. I'm pretty sure ya'll know I'm going to ask which one is the faulty one, but my next question is, which sensor does what for the car? Also, I recently switched to larger tires, namely P195/65/R15; stock is P195/60/R15. Would this have caused the speed sensor(s) to go bad?

[HenRoc]

After checking the manual, I see there are three speed sensors on the car. The main shaft sensor, the counter shaft sensor, then that big speed pulse device thing that sits on top of the transmission near the differential housing. I'm pretty sure ya'll know I'm going to ask which one is the faulty one, but my next question is, which sensor does what for the car? Also, I recently switched to larger tires, namely P195/65/R15; stock is P195/60/R15. Would this have caused the speed sensor(s) to go bad?

No. The mainshaft speed sensor is faulty. If you have the manual then do a voltage test on the VSS and Mainshaft sensors..that will narrow down your problem.

[psawall]

Accrdkid, you can't diagnose which one is faulty without an error code, and the counter and main shaft sensors are resistance tested.

otacon122, here is what you do:

1. Disconnect the connector to the main shaft sensor and measure the resistance with a multimeter. You should get between 400-600 ohms of resistance. If not, it's faulty and you need to replace it.

2. Do the same thing for the counter shaft sensor. The resistance should be the same. If it's not within spec, replace it.

3. If both of those sensors check out okay, then it's your speed sensor. Testing this sensor is a bit more difficult and you need some special tools, so just replace it. The speed sensor for the 90-91 is different from the 92-93 accords, so make sure you get the right one.

***EDIT***

Sorry Accrdkid, there was a TCU code in the first post. TCU code 4 is for the speed sensor (VSS), not the main shaft. So Otacon122, just replace the darn speed sensor. You can check the other two out if you have a multimeter just to make sure, but you should get codes for them if they were bad (TCU err 9 for counter shaft, and TCU err 15 for main shaft). Also, if either of those were bad, you would be experiencing different issues like lock-up clutch not engaging or hard shifting. Lock-up clutch will not engage with a fautly speed sensor too (as I have experienced), but you also have the added issue of no speed on the speedometer. So, in conclusion, everything is pointing to VSS.

[otacon122]

I'm getting ECU error code 17 and TCU error codes 4, 14, and 15. TCU code 15 is apparently the Main Shaft Speed Sensor.

[otacon122]

I am going to give the engine bay a thorough wash-down and get all the caked-in oil and grease and stuff off everything then reset the ECU and see if that makes a difference. The engine bay is in dire need of a wash, and its so bad now that it will take a power washer or some heavy-duty degreaser to get it clean.

Edit: Found the problem! After resetting the ECU and taking it on a driving test, I again tried the jumper and this time, it only spits out TCU code 14. How do I fix the shorted FAS wire between the ECU and TCU?

[psawall]

Oh, that's bad. Probably a bad TCU or you just have a short in the wiring somewhere. I would pull the TCU out and open it up. See if you find any swollen or leaking capacitors and look for anything that looks burned. Or just stick your nose in there and take a whiff...it is smells like burnt electronics, it's probably a bad TCU. Given all the differnt error codes you've gotten, I'd say this is your problem. Did you ever test the main and counter sensors?

[otacon122]

Oh, that's bad. Probably a bad TCU or you just have a short in the wiring somewhere. I would pull the TCU out and open it up. See if you find any swollen or leaking capacitors and look for anything that looks burned. Or just stick your nose in there and take a whiff...it is smells like burnt electronics, it's probably a bad TCU. Given all the differnt error codes you've gotten, I'd say this is your problem. Did you ever test the main and counter sensors?

It still kicks up a code 15, so the problem is erratic - it doesn't happen all the time. Unfortunately, there are several speed sensors on the car, and I don't know which one to change out. There are speed sensors on the wheels, the speed pulse thing on the differential housing, and then the main shaft and counter shaft speed sensors.

[drew12000]

It still kicks up a code 15, so the problem is erratic - it doesn't happen all the time. Unfortunately, there are several speed sensors on the car, and I don't know which one to change out. There are speed sensors on the wheels, the speed pulse thing on the differential housing, and then the main shaft and counter shaft speed sensors.

http://www.cb7tuner.com/vbb/showthread.php?t=115100