No speedometer....Speed Sensors??

[LS1FJ40]

@SmokingRocks thank you for the incredible break down of the speedo system. My speedo is very occasionally intermittent. No CEL. The speedo seems to "stick" for a second then jump up to the correct speed. Nothing worth digging in to yet but helps me think about the cluster in the future.

 

[ampline]

does your cruise control work?

YES ---> REPLACE INSTRUMENT CLUSTER
NO-----> VERIFY CONTINUITY BETWEEN CLUSTER AND VSS

• IF CONTINUITY PASSES INSPECT / REPLACE VSS
• IF NO CONTINUITY TRACE WIRE HARNESS UNTIL BREAK IS FOUND

Easy to follow advice!!! Thank you!

 

[gsi18867]

Check the large white plugs on top of the transmission. These are the two covered in foam just under the firewall. If the connections are not completely snapped together or are damaged, the speedometer can malfunction or jump. After I reinstalled my engine, I didn't fully connect one and the speedometer would jump after the engine was warmed up, then quit entirely.

 

[KolePilot]

Ok, this all makes perfect sense. My dad just had a used 1fz swapped into his 95. Speedo is jumping and cruise doesn't work. He has a CEL but we haven't been able to check it yet. Based on @SmokingRocks input I'd conclude that it's not a gauge, but a VSS or wiring issue.

HOWEVER, we have a different factor to add in. When the vehicle is in Neutral or Park and you rev the engine, the speedo gauge will bounce with the engine revs. Not matching the revs like a tack, but jumping randomly as you rev the engine. This makes me think a bad ground. I am a complete electrical neophyte, so I'd appreciate any input. We did not do the work ourselves, so I'm not sure where all of the grounds are or connectors in the tach wiring.

 

[SmokingRocks]

bad ground or there is a connector that is not plugged in / plugged into something else.

 

[davesax36]

My speedo finally gave up, AND I got a code to work with (0500). I'll be pulling the plug to test the VSS1 in the morning, and clean VSS2 as well. Hopefully things will come back to life. I really don't want to spend $$$ on a part that looks as clean as it did last time I cleaned up under there two weeks ago.

 

[aktundra]

I have done a LS swap, and have not been able to get the Speedo to work.
Do I need cruise control and/or the tac to be functioning for the Speedo in a 1993 to work ?

 

[thatcabledude]

I have done a LS swap, and have not been able to get the Speedo to work.
Do I need cruise control and/or the tac to be functioning for the Speedo in a 1993 to work ?

No.

Is the sensor on the T-case getting power? When I did mine I inadvertently deleted the sensor power wire from what was reused of the engine harness. Others have done the same.

 

[aktundra]

No.

Is the sensor on the T-case getting power? When I did mine I inadvertently deleted the sensor power wire from what was reused of the engine harness. Others have done the same.

I’ve got 12v & ground at the t-case sensor and it’s a new sensor. The rig was a junker I bought specifically for the swap, didn’t drive it much before the swap. Beginning to think the Speedo never worked & the issue is in the cluster

 

[Rrrosco]

Hi guys, I've just had my speed sensor sieze up on my 94 80 series, I'm looking at replacements and finding a huge range of prices from $20 to $400 (in Australia). Has anyone here had experience with the cheapo ones? I'm leaning towards trialing a cheap one to see if it happens again or if there is an underlying problem etc...
Cheers

 

[light1]

How do you define cruise control "working"? My cruise control light comes on (Cruise), but I can't set it, speedo/tacho don't work. I'll check the rest of the VSS/Tranny connections

 

[light1]

Started driving around and the speedo/odo came back. Check engine light with OBD reader and it said speed sensor (VSS #1 ?) - I reset it and it has not come back ...

I have a spare Instrument cluster now...maybe I'll install it on my son's tricycle

 

[thelal]

We are talking about the VSS #1 on the transfer case, not the VSS #2 on the transmission. ..

I've a P0500 error and appears the wiring cable that comes off the speedo at the transfer case and goes forward to the transmission where it plugs in (3 wire loom) looks "broken"
Anyone know what this part# is for this wiring loom. I cannot find it on any diagrams

 

[mudgudgeon]

I've a P0500 error and appears the wiring cable that comes off the speedo at the transfer case and goes forward to the transmission where it plugs in (3 wire loom) looks "broken"
Anyone know what this part# is for this wiring loom. I cannot find it on any diagrams

There's a plug / connection for this three wire harness on top of the tcase.
Mine has a broken harness connector here. No idea how it manages to get broken in this spot, but mine crumbled to bits.
You might have the same problem

There's a guide to factory harness components in the resources section in the forum menu.

 

[Malleus]

It's raining here, so I'm not crawling under mine until tomorrow, but if it's this:

I think it's this:

That's the only three wire connector in the transmission circuit. The complete EWD's are in the resources section: a) connectors [ppg 30-39]; b) 1995, Drivetrain, Electronically Controlled Transmission (ECT) and AT indicator (ppg 130-137)

I think the circuits are the same for the last three years.

 

[Yota4x4orWife]

An easy way to tell if the vss on the transmission is working is to plug in a scan tool to the obd2 port (‘95+ models?) and read the live data.

My Speedo (1996 fzj80) doesn’t work but computer receives speed data and cruise control does work. I plugged in a scan gauge 2 and used the speed correction function to get my actual speed due to larger tires.

Link below is a guy who soldered jumpers on the back of the cluster and was able to fix the speedometer



Cheers

 

[thelal]

There's a plug / connection for this three wire harness on top of the tcase.
Mine has a broken harness connector here. No idea how it manages to get broken in this spot, but mine crumbled to bits.
..

great

 

[leonelcanut]

Ok, this all makes perfect sense. My dad just had a used 1fz swapped into his 95. Speedo is jumping and cruise doesn't work. He has a CEL but we haven't been able to check it yet. Based on @SmokingRocks input I'd conclude that it's not a gauge, but a VSS or wiring issue.

HOWEVER, we have a different factor to add in. When the vehicle is in Neutral or Park and you rev the engine, the speedo gauge will bounce with the engine revs. Not matching the revs like a tack, but jumping randomly as you rev the engine. This makes me think a bad ground. I am a complete electrical neophyte, so I'd appreciate any input. We did not do the work ourselves, so I'm not sure where all of the grounds are or connectors in the tach wiring.

Hi, have the same issue, did you find what it was? Cheers

 

[gsi18867]

Check the harness connection, the one wrapped in foam sitting in the transmission tunnel on top of the trans. There’s not much slack in it and it’s sometimes hard to fully connect after an engine swap. Ask me how I know . My Speedo had the same issue, jumpy, dead. But it did help to keep about 5K mikes off the odo

 

[AdamKFarmer]

Wanted to ask the experts in this thread about my cruise control issue. I rebuilt the head on my FZJ80 and after replugging in everything my cruise control doens't work. The speedo and tach work fine, no cruise codes. I haven't performed the VSS tests yet, but everything looks good. Any thoughts?