speedo not working Code #42

makarov9 · Apr 10, 2012

My speedometer doesn't work 85% of the time, coming on and off iradically, mostly off, but I was aware of this when I traded for it, hoping it was an easy fix. I went for a 200 mile ride today and the bike ran great, but the speedo was of course acting up, not working most of the time, sometimes coming on and registering 8mph when I was probably going 40, stuff like that, and my check engine light would come on and go off, sometimes staying on for long periods of time. I'm assuming the problem with the speedo is throwing a code. My dash shows a code #42 when my key is turned on, before I start it. The previous owner has put a small black box under the tank with thick red wiring, it has an SH or HS on the reverse side and has about 10 tiny white switches, says "dip" or something, it has 2 factory plugs on the end. I don't know what this is, could it be causing my problem if it's gone bad or something? It looks to be plugged into and bridged between the, what I think is the speedo sensor plugs, but I could be wrong. I disconnected the 2 factory plugs that are plugged into the black box from my factory plugs and plugged them back together, but it didn't do anything, my bike's check engine light is still on and code "42" is still on the dash.

I'm a veteran rider of 25yrs on many different kinds of bikes, but I've only owned 2 Yamaha sportbikes, so I'm a bit new to their quirks. I'm looking for advice if anyone has any.

mave2911 · Apr 10, 2012

makarov9 said:
My speedometer doesn't work 85% of the time, coming on and off iradically, mostly off, but I was aware of this when I traded for it, hoping it was an easy fix. I went for a 200 mile ride today and the bike ran great, but the speedo was of course acting up, not working most of the time, sometimes coming on and registering 8mph when I was probably going 40, stuff like that, and my check engine light would come on and go off, sometimes staying on for long periods of time. I'm assuming the problem with the speedo is throwing a code. My dash shows a code #42 when my key is turned on, before I start it. The previous owner has put a small black box under the tank with thick red wiring, it has an SH or HS on the reverse side and has about 10 tiny white switches, says "dip" or something, it has 2 factory plugs on the end. I don't know what this is, could it be causing my problem if it's gone bad or something? It looks to be plugged into and bridged between the, what I think is the speedo sensor plugs, but I could be wrong. I disconnected the 2 factory plugs that are plugged into the black box from my factory plugs and plugged them back together, but it didn't do anything, my bike's check engine light is still on and code "42" is still on the dash.

I'm a veteran rider of 25yrs on many different kinds of bikes, but I've only owned 2 Yamaha sportbikes, so I'm a bit new to their quirks. I'm looking for advice if anyone has any.

Sounds like a speedo adjuster - you should be able to unplug it and see if that fixes the problem.

Cheers,
Rick

Nelly · Apr 11, 2012

makarov9 said:
My speedometer doesn't work 85% of the time, coming on and off iradically, mostly off, but I was aware of this when I traded for it, hoping it was an easy fix. I went for a 200 mile ride today and the bike ran great, but the speedo was of course acting up, not working most of the time, sometimes coming on and registering 8mph when I was probably going 40, stuff like that, and my check engine light would come on and go off, sometimes staying on for long periods of time. I'm assuming the problem with the speedo is throwing a code. My dash shows a code #42 when my key is turned on, before I start it. The previous owner has put a small black box under the tank with thick red wiring, it has an SH or HS on the reverse side and has about 10 tiny white switches, says "dip" or something, it has 2 factory plugs on the end. I don't know what this is, could it be causing my problem if it's gone bad or something? It looks to be plugged into and bridged between the, what I think is the speedo sensor plugs, but I could be wrong. I disconnected the 2 factory plugs that are plugged into the black box from my factory plugs and plugged them back together, but it didn't do anything, my bike's check engine light is still on and code "42" is still on the dash.

I'm a veteran rider of 25yrs on many different kinds of bikes, but I've only owned 2 Yamaha sportbikes, so I'm a bit new to their quirks. I'm looking for advice if anyone has any.

If you post a picture of the wiring assembly. Our resident electronic "Guru" Cliff should be able to help sort the issue.

Nelly

TownsendsFJR1300 · Apr 11, 2012

From the fault codes section listed in this section at the top:

Fault Code: 42
Diagnostic Code: 07, 21
Symptom: No normal signals are received from the speed sensor; or, an open or
short circuit is detected in the neutral switch.
Probable cause of malfunction:
Open or short circuit in wiring harness.
Defective speed sensor.
Malfunction in vehicle speed sensor detected unit.
Defective neutral switch.
Malfunction in the engine side of the neutral switch.
Malfunction in ECU.

The speedometer pickup is at the rear of the engine and the wire lead goes up either below the tank, or under the seat(forgot). It'll have a three wire connector plugging into the main harness.

This plug is where you plug in a "Speedohealer" inline if you were inclined.

I would check the contacts, clean and put dilectric grease in the connector and try that. If that doesn't work, you'll have to test the pick up sensor (should be in the shop manual). It is not unusual, especially if you live near the water, to get corrosion (and problems) in the connector.

That box sounds like an aftermarket speedometer healer... Besides disconnecting the box as it may likely be the culprit (I would) , disconnect the battery for 15-20 minutes and re-set the ECU...

makarov9 · Apr 11, 2012

Pictures, the way it sets on my bike now. Thanks guys for the advice so far, keep it coming, I want to fix this easily. If this is a speedo healer, I don't care much about it if you guys think it's what is causing the problem

Device in question

Factory plugs and where it's connected

Dash code 42 with check engine light, it stays on when I start the engine

Motogiro · Apr 11, 2012

Maybe a shot in the dark...Make sure you have that device out of line. Disconnect the negative lead to the battery for a few minutes. Reconnect negative lead and see if it behaves. The ECU may have learned some bad code in the volatile memory and this may clear it anderror code that's being thrown...

makarov9 · Apr 11, 2012

Finally got the previous owner to contact me. He said that the device was installed shortly after he bought it new in 2005, he said "it helps smooth out the throttle or something", really vague. I don't believe him and it's unusual to not know what you install on your own bike. He couldn't tell me exactly what it was or what it did. He said that he had the fuel injectors cleaned about 2mths ago and after that the speedo gave problems, but worked perfectly before that

TownsendsFJR1300 · Apr 11, 2012

Its got the initials of SH which leads me to believe its a Speedohealer, a very, very early version... Mine is nothing like that..

It makes sense if it failed, you'd get mixed signals, if any, to the speedometer (erratic speedometer) and then it'd also trip up the ECU as its not getting the correct signal from the speed sensor..

As Cliff stated, pull it out altogether, disconnect the battery and try to re-set the ECU.

The slide settings reminds me of the old garage door opener settings (before roaming automatic settings), perhaps that's what they used back then.

A call to Speedohealer might shed some light on the unit...

makarov9 · Apr 11, 2012

I yanked the box out and disconnected it, plugging the factory plugs back together, disconnected the battery, waited and reconnected it. The code 42 is still showing and check engine light still on, nothing has changed, I can't seem to clear the code. I got into the diagnostic settings via help from a reluctant yamaha tech and the neutral switch is fine, but the speed sensor is not communicating to the computer, according to diagnostic testing. Is it possible to have a bad speed sensor on a bike with only 1900 miles? Weird. Now I'm trying to locate exactly where the speed sensor is on the bike. I'm assuming that it just unplugs and I can replace it easily once I find it, hope I'm not wrong.

Motogiro · Apr 11, 2012

You should be able to follow the wire from the plug that the SH was attached to.

makarov9 · Apr 11, 2012

Cool, thanks, I'll try to find it in the morning.

You guys have been great :rockon: Thanks for helping out a new FZ rider

speedo not working Code #42

makarov9

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mave2911

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Nelly

International Liaison

TownsendsFJR1300

2007 FZ6

makarov9

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Motogiro

Vrrroooooom!

makarov9

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TownsendsFJR1300

2007 FZ6

makarov9

Junior Member

Motogiro

Vrrroooooom!

makarov9

Junior Member

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