Wacky Instrument Cluster Issue

[hamsandwiches]

Hello folks, long time lurker
Bought my 2000 sr5 4x4 in September with 130k now at 137k

I have done as preventative:
TB/WP, tensioners, new rad, new belts, every single fluid on the vehicle except refrigerant, new tires, rear bearings/seals, maf, plugs, wires, battery, all filters, o2 sensor, etc

The issue began a few hundred miles after plugs/wires/maf clean

About every 100 miles, the tach and speedometer stay in position (will not move from their current position), the fuel gauge goes to half and the odometer reads "777777" but its half digits. Vehicle runs/drives perfectly before and during when this happens. Temp gauge is unaffected and all the cluster lights are working.

Only thing that 'resets' it is to pull over, shut off, disconnect and reconnect battery. Then the gauges function fine for another 100ish miles until it happens again. It will not fix it to smack the dash/cluster or if I just shut the car off and turn it back on.

Pulled the cluster and cleaned all plugs - no change, checked what grounds I could find. Truck has zero rust

Internal issue with the cluster? ECM/PCM? Some other ground? Hmmm

This one's got me stumped. Getting pretty annoying. :ybrick:

Thanks for any insight!!

 

[phattyduck]

That almost sounds like a factory test mode for the gauge cluster... (not for diagnosis, something that may have been used during manufacturing the cluster)

Do you have a scangauge or similar that can report what the ECU is reading for speed when this happens?

I would suspect this is an issue internally in the gauge cluster...

-Charlie

 

[hamsandwiches]

What do you mean factory test mode? Like to adjust the gauges ?

I have a cheap Walmart Code scanner I don't believe it will give live data. I will try though.

I would venture to guess the ECU is getting the correct speed signal because the shift points are unchanged when it happens.

This is a long shot - could it be an alternator issue? No other electrical issues have surfaced

Truck gives 13.9-14.1v @ 1500 RPM and 13.7v @idle (650 RPM)

Is that was you guys get?

I'm leaning toward replacing the cluster - anyone familiar with how to load the mileage on one?

Thanks!

 

[phattyduck]

Your charging voltage sounds fine. 13.6V+ when hot, 14+ when cold. It can be a bit lower at idle if you have lots of stuff turned on (headlights, brake lights, interior fan, etc.).

Shift points are handled using shaft speed sensors in the transmission, not the speedo signal that is routed through the gauge cluster. It has to do this due to the 2-speed transfer case. The gauge cluster speed signal comes from the ABS module (wheel speed sensors), that then routes it to the ECU. Tach signal comes from the ECU to the gauge cluster.

By factory test mode, I mean for the factory that made the gauge cluster. So, Toyota wouldn't even know how to set/use/adjust. It would be used for setting the needles in the correct location during assembly, probably. No way to prove that though.

At this age you don't legally need to have the correct mileage on the odometer. I bet there is a service out there that can do it though. You might also be able to swap your speedo/odo module into an otherwise working cluster. I don't know where the mileage is stored on the cluster though...

-Charlie

 

[hamsandwiches]

Ok, so if the ECM gets speed signals from shaft sensors, and the cluster gets it from abs sensors - if the signal was wrong would it not throw an abs error code?

So at this point it would seem the cluster is always recieving the correct signal, just not displaying it properly. Just strange how disconnecting/reconnecting the battery fixes it for a while.

I guess it is resetting all power to the cluster?

Plan is to go to the yard this week and see if I can find a cluster.

Will 01 and 02 clusters work in an 00 even though there's no VSC stuff?
and the 99 and 00 are identical correct?

Yeehaw

 

[phattyduck]

The ECU controls transmission shifting from sensors exclusively inside the transmission. It still expects to see a speedometer signal separately from the gauge cluster (not used for shift logic through) - and will throw a code if that signal is missing for a while, but not immediately.

Look for a '99/'00 cluster. Since you have an SR5, you can get the cluster from any V6 auto 2WD or j-shift 4WD.

If you do find one, the first test would just be to run the new cluster to see if that fixes the problem. The next step would be figuring out if you can make a frankenstein cluster from the two that will work and keep your odo correct.

-Charlie

 

[APhelps]

The ECU controls transmission shifting from sensors exclusively inside the transmission. It still expects to see a speedometer signal separately from the gauge cluster (not used for shift logic through) - and will throw a code if that signal is missing for a while, but not immediately.

Look for a '99/'00 cluster. Since you have an SR5, you can get the cluster from any V6 auto 2WD or j-shift 4WD.

If you do find one, the first test would just be to run the new cluster to see if that fixes the problem. The next step would be figuring out if you can make a frankenstein cluster from the two that will work and keep your odo correct.

-Charlie

I do know that you can make a frankenstein cluster from a 96-98 4Runner (2wd/4wd) doesn't matter (the tachs are different for a 4 cylinder / 6 cylinder though). The tacho and speedo/odometer can be swapped over. 99+ I don't have a clue though.

 

[phattyduck]

99+ I don't have a clue though.

The '99 cluster is much more complicated than the earlier one. It controls some odd stuff (auto light turn off, etc.). I have replaced the rear flex circuit board on mine, but I didn't get any deeper into it than that - there are definitely multiple logic boards, etc. on there.

-Charlie

 

[DaMonkey]

Maybe worthwhile trying to isolate the problem first.

You know battery unhook resets it. What if you unplug the cluster harness instead? If that resets it then you know it’s cluster. If not, then try unplug ecu.

Does the cluster still get power while key is out? Why?

 

[phattyduck]

Does the cluster still get power while key is out? Why?

The cluster has constant power to keep the ODO Trip memory, control the lights, etc.

-Charlie

 

[Reinout]

I'm just going to toss this in as an idea before buying/modding: Have you checked ALL the connections: while the cluster might be getting power maybe there's a connector, somewhere, that is just barely not clipped in right.

I thought I was going to have to replace a few parts, but it turned out that a connector had done exactly what I just said, clip didn't "clip".

 

[hamsandwiches]

I'm just going to toss this in as an idea before buying/modding: Have you checked ALL the connections: while the cluster might be getting power maybe there's a connector, somewhere, that is just barely not clipped in right.

I thought I was going to have to replace a few parts, but it turned out that a connector had done exactly what I just said, clip didn't "clip".

The reason I don't think it is a loose connection is because the issue happens almost exactly every 100 miles.

Also, how would disconnecting/reconnecting the battery resolve a bad contact?

Yes the cluster gets power constantly - although it should not show the mileage with the key out - it does when the "777777" issue happens


DaMonkey, Its really difficult to replicate the issue because you have to drive it, and when it happens I want to immediately pull over and fix it. Pulling the cluster in a parking lot somewhere is less than ideal - although not impossible. Also, I wouldn't pull the cluster without disconnecting the battery in the first place for safety.

Given how inexpensive they are, I think I'm going to replace the cluster with one from a yard and go from there.

Thanks!!

 

[Renegade_Medic]

I would wager that it is a problem with the board inside the cluster. The ECU has nothing to do with the cluster. They run independently of eachother, save for RPM.

If it's happening at 100 miles, its likely something tripping it in the odometer. As stated before, you could try leaving the truck running and unhook the cluster and plug is back in to see if fixes your problem. If it goes back to normal, you definitely have a problem in the cluster. There is a company out there somewhere that you can send the cluster to and they will repair the circuit board. Mine burned up the fuel level sender and I opted to just replace the entire cluster with a salvage yard one.

Good luck

 

[hamsandwiches]

Ok so the problem now happens almost every time I drive the vehicle. Although now instead of going to zero, the needles stay where they are and will not move, and sometimes the gas gauge go to completely full and not half like before when it happens. All symptoms are corrected when battery negative is removed/put back on.


pulled a cluster at the yard for $26 and installed it today - guess I have 246000 now lol.

I will let you guys know if this fixes the issue.

Another long shot idea - could it be the notorious fuel gauge/sending unit thingy that happens on 99 and 00s? Not sure if that could affect the other gauges?

Thanks again 4runner gods

 

[hamsandwiches]

So far so good, added about 100 miles to new cluster.

Thanks everyone!!!!

 

[hamsandwiches]

Thought it was fixed with new gauge cluster because no issues for 900 miles.

Happened again about 5 times on a camping trip this weekend.

Only once did the gauges flick back on - all other times i had To pull over and take battery off/reconnect.

Where should I look for broken/exposed wires?

With the new cluster in there, I'm really running out of ideas. No other electrical issues at all. Everything works fine expect gauges.

The problem is presenting itself at much rarer times now though. Like I said it didn't for 900 miles, then it did it twice in like 5 miles.

Taped up some exposed/broken wires going into the back hatch but that did not change anything, it has done the issue since then. A toyota mechanic suggested looking at that segment of wires.

I like driving this thing but man this is getting annoying lol

Thanks guys/gals

 

[hamsandwiches]

Would this be something related to the fuel gauge issues I have heard about?

When the gauges are working, the fuel gauge is always pretty accurate - never bounced around or anything weird.

Seems swapping the cluster has done nothing.

Grounding issue? What I can't understand is why the only way to fix it is to disconnect/reconnect battery

I'm running out of ideas.

 

[Renegade_Medic]

Yeah, I got nothing. It is odd that the other cluster worked for a long time. Sounds like something is shorting out and killing the clusters.

 

[hamsandwiches]

Yea, because it SEEMS to be getting slowly worse with both clusters.

I just have no idea where to look for shorts?

What ECU is linked to the cluster?

Should I start replacing electronic modules like the body ECU, powertrain ECU?

Just weird how I have zero other electrical issues.

Had a volt gauge wired with an add a fuse to one of the 10 A fuses on the body ECU, removed that when the issue started happening, but obviously to no avail.

Could that have done permanent damage to the body ECU?

 

[hamsandwiches]

Any ideas? About to drive another 500 miles not looking forward to pulling over randomly to fix the gauges lol

Thanks again folks