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8th Gen Gauges



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On my 98 corolla, there is no tachometer. The speedometer gauge has an LCD screen which displays the odometer and tripmeter. The fuel/temp gauge doesn't have an LCD.

My question is: on an 8th gen. gauge WITH TACH, what does the LCD under the tach display?

It displays the outside temperature. NOTE: if you want to swap in a cluster with a tach, it will work - just plug and play - but your mileage readout will be different and the temp will display -E-.

It displays the outside temperature. NOTE: if you want to swap in a cluster with a tach, it will work - just plug and play - but your mileage readout will be different and the temp will display -E-.

So, the mileage is not recorded and stored in the ECU? Its stored in the cluster itself? Also, why would the temp display E? Do I not have that wire that reads outside temp?

So, the mileage is not recorded and stored in the ECU? Its stored in the cluster itself? Also, why would the temp display E? Do I not have that wire that reads outside temp?

Nope - mileage is on the cluster itself - not a deal breaker as you could simply transfer the speedo from one to the other. Correct on the temp - models without the tach as OEM are missing the thermistor that measures temperature.

 

 

Correct on the temp - models without the tach as OEM are missing the thermistor that measures temperature.

Is there not a way to install the missing thermistor? I'm guessing that the wiring harness would still have the wire needed for the thermistor. Where is the thermistor usually located?

I've been lamenting the lack of a tach in my 98 Corolla and was very pleased to find this thread. Much better solution that an aftermarket tach.

Thanks,

jim

Thermistor is located by the front grille - may luck out and have the wiring already there, just have to add the sensor. Easiest way to get one if from a salvage yard - dealership would probably not stock that thermistor - have to order it for you.

Is the attached pic the right connector? Sorry for the poor quality, it was taken with a cell phone. This is behind the bumper, directly under the hood latch, about 8 to 12 inches down I'd guess.

[ATTACH]1[/ATTACH]

Is the attached pic the right connector? Sorry for the poor quality, it was taken with a cell phone. This is behind the bumper, directly under the hood latch, about 8 to 12 inches down I'd guess.

[ATTACH]1[/ATTACH]

That could be it; since it is not connected to anything.

 

 

That could be it; since it is not connected to anything.

My concern is that it might be for fog lights or something else I haven't even thought of. However, it does appear to be in the correct location for the thermister fish mentioned.

I do wish the car had fog lights. Maybe someday I'll get a factory service manual and figure out how to get more of the features I want into this plain little CE.

Yup - that is the thermistor. You can double check by probing pins #8 and #16 on the wiring harness "A" - the 16 pin wire bundle that goes to the back of the cluster (it is the largest of the 4 bundles back there).

Thanks again to everyone in this forum for all the wondefully helpful information.

I acquired via ebay a used instrument cluster with tach, and swapped my speedo (including odometer) into it, and now I have a functional tach!

I do have the -E- on the LCD display instead of a temperature, but that's because I don't have the thermister as fish has said. I'll hopefully find one that'll plug into that empty connector in my car and have that feature working too. However, even without that feature, having a tach is awesome!

fish, if you ever find yourself on the eastern side of the bay, give me a shout. I'll treat you to a beverage of your choosing. default_smile

thanks again,

jim

That's great news that you now have a working tachometer.

What are you doing with your old instrument cluster?

That's great news that you now have a working tachometer.What are you doing with your old instrument cluster?

Well, years ago I had a ford probe, and I went nuts with "upgrade" and "tweaks". Granted, the mazda 2.2L Turbo engine was fun, but I reached a point where I had more projects going on than I could keep straight, and the car was in a bazillion pieces, and I never did get it back together. At one point I had 3 of them (a parts donor car, an engine donor car, and the one I was trying to get back in shape). Then the county came along and said I was in violation of the junk vehicle laws, and off to the scrapyard they went.

I've decided I'm not going to go nuts with this vehicle. I want to keep as close to stock as possible in most cases. So when I need to make a hole in a plastic panel, I first buy a replacement panel and put the original in a safe storage place, so I can put it back if I ever need to.

My plan is to hang on to the original instrument cluster for this reason. However, I might get rid of it on ebay after several month. I'm just not sure yet...

I did end up re-using the speedo from the original panel, and I transferred all the lights rather than painstakingly testing the lights in the new panel. Also, the new panel has a problem with the left turn signal indicator not lighting. If the highbeams happen to be on, the left blinkers cause the highbeam indicator to blink. I don't know if the original panel had that problem. I'll track it down eventually. Hopefully something super simple.

Would an 8th gen instrument cluster work in your 7th gen cars?

Oh yeah, this was also the first instrument panel swap I ever did on a vehicle with no speedometer cable. default_blink

That's great news that you now have a working tachometer.What are you doing with your old instrument cluster?

Well, years ago I had a ford probe, and I went nuts with "upgrade" and "tweaks". Granted, the mazda 2.2L Turbo engine was fun, but I reached a point where I had more projects going on than I could keep straight, and the car was in a bazillion pieces, and I never did get it back together. At one point I had 3 of them (a parts donor car, an engine donor car, and the one I was trying to get back in shape). Then the county came along and said I was in violation of the junk vehicle laws, and off to the scrapyard they went.

I've decided I'm not going to go nuts with this vehicle. I want to keep as close to stock as possible in most cases. So when I need to make a hole in a plastic panel, I first buy a replacement panel and put the original in a safe storage place, so I can put it back if I ever need to.

My plan is to hang on to the original instrument cluster for this reason. However, I might get rid of it on ebay after several month. I'm just not sure yet...

I did end up re-using the speedo from the original panel, and I transferred all the lights rather than painstakingly testing the lights in the new panel. Also, the new panel has a problem with the left turn signal indicator not lighting. If the highbeams happen to be on, the left blinkers cause the highbeam indicator to blink. I don't know if the original panel had that problem. I'll track it down eventually. Hopefully something super simple.

Would an 8th gen instrument cluster work in your 7th gen cars?

Oh yeah, this was also the first instrument panel swap I ever did on a vehicle with no speedometer cable. default_blink

The instrument panel will probably not work for me, I was just curious as to what you would do with it.

 

I have a lot of left-over parts in my garage and was wondering what I should do with them.

I had another engine and now I have bought a car to put it in from e-Bay.

That means the bad engine I take out will end up in my pile of parts.

Looks like I've hijacked this topic. default_unsure

In any case, I figured I'd update the information about my instrument cluster swap in case anyone was interested.

I noticed first that the left turn signal caused the high beam indicator to flash if the high beams were on. But not if they were off. And the left turn signal indicator remained dark. Yesterday I noticed that turning on the rear defrost caused the left turn signal indicator to light.

After some deliberation, I decided to put things back to the original configuration.

First though, I decided to scan the circuits into a computer so I could figure out everything that is different about them. The instrument cluster is longer than the scanner, so I had to scan from each end then attempt to stitch them back together afterwards.

Here's my original cluster:

[ATTACH]3[/ATTACH]

and here's the one I bought:

[ATTACH]4[/ATTACH]

I circled the area that is different for the turn signals in blue. I also made some notes about all over the place.

In any case, perhaps someone else will find these useful. I'm still working on identifying all the differences.

jim

ok, I've laboriously traced out each connection from the connectors to the items they connect to. I did this by drawing a different colored line on each trace in the scans of the circuits.

I don't have any official docs (like a factory service manual, or factory wiring diagram), so in the absense of the correct names for the connectory, I simply named them C1 thru C5, with C2 being the 3 pin ABS related connector, counting from left to right with the connectors at the top of the board from the back. In other words, from left to right in the pictures I posted in the previous post. I numbered the pins the same way, from 1 to whatever.

Here are the changes:

C1 pin 9: original goes to: IG+ for Fuel and Temp gauges, and these lamps: CEL, Windshield Washer, O/D off, Oil, Cruise, Seatbelt, Brake. New one goes to: IG+ for Fuel, speedometer, tachometer, and temp gauge. These lamps: CEL, WW, O/D, ABS, Low Gas, Brake, Seatbelt, Oil, Cruise

C2 pin 2: original goes to: C3 pin 2, Rear Defrost Lamp, odd circuit behind speedo, L and R turn signals, High beam. New one goes to: C3 pin 2, odd circuit behind speedo, L and R turn signals.

C3 pin 10: original goes to: SE on speedometer, E on fuel gauge, C4 pin 2. New goes to: C4 pin 2, C4 pin 1, SE on speedometer and fuel and tachometer

C3 pin 11: original goes to: Rear Defrost. New goes to Left Turn Lamp

C3 pin 12: original goes to: Left Turn Lamp. New goes to: high beam other leg.

C4 pin 1: original isn't connected, new is: C4 pin 2, C3 pin 10, SE on speedometer and fuel and tachometer

C4 pin 2: original is: SE on speedometer, E on Fuel Gauge, C3 pin 10. new is: C4 pin 1, C3 pin 10, SE on speedometer, fuel, tachometer.

C4 pin 9: original isn't connected, new is: TAM on tachometer

C4 pin 14: original isn't connected, new is: IG- on tachometer

C5 pin 9: original is +B on speedo, door ajar lamp, new is: +B on speedo, +B on tach, door ajar lamp

I don't think I did any damage with the incorrect cluster in. However, I'm hesitant to try it in the car again. I'm keeping my eye open for a different cluster

I'm wondering if this cluster didn't perhaps come from a different model of toyota. Does anyone know how interchangable they might be? I know the ebayer said it came from a corolla, but you never know. Of course, a different model year might explain it.

jim

Clusters from the same generation and market (ie. 8th gen (1998-2002) for North American market only) - are plug and ply. There are some differences - but they wiring is largely the same between the two (connector wise).

I've got some scanned FSM diagrams on my Photobucket site - might be useful:

https://img.photobucket.com/albums/v620/fis...usterwiring.jpg

https://img.photobucket.com/albums/v620/fis...hgenCluster.jpg

default_biggrin Thanks for the very detailed wire tracing, even that is covered in that detail in the Factory service manual without breaking out the separate wiring diagram.

Clusters from the same generation and market (ie. 8th gen (1998-2002) for North American market only) - are plug and ply. There are some differences - but they wiring is largely the same between the two (connector wise).

I've got some scanned FSM diagrams on my Photobucket site - might be useful:

https://img.photobucket.com/albums/v620/fis...usterwiring.jpg

https://img.photobucket.com/albums/v620/fis...hgenCluster.jpg

default_biggrin Thanks for the very detailed wire tracing, even that is covered in that detail in the Factory service manual without breaking out the separate wiring diagram.

I appreciate the scans, they've been helpful.

I have a 1998 corolla. However, the instrument cluster that it came with does not match your scans. B3 on my instrument cluster is the rear defrost lamp, and on your scans, there's no rear defrost. In fact, on my replacement cluster, the lamp for the rear defrost doesn't even have any traces going to it.

Everything else matches pretty close.

pin - Scan - mine - replacement

B2 - Light Control - L. Turn - High Beam

B3 - L. Turn - R. Defrost - L. Turn

These are the most significant differences.

I wonder if later year models might not have moved the rear defrost indicator to the button, and eliminated the need in the instrument cluster.

On the plus side, I used a tone generator and tone tracer to verify that the mystery plug in my grill area is in fact the outside ambient air temperature sensor connector. It connects to pins A8 and A16.

Thanks again fish.

jim

ok, I've laboriously traced out each connection from the connectors to the items they connect to. I did this by drawing a different colored line on each trace in the scans of the circuits.

I don't have any official docs (like a factory service manual, or factory wiring diagram), so in the absense of the correct names for the connectory, I simply named them C1 thru C5, with C2 being the 3 pin ABS related connector, counting from left to right with the connectors at the top of the board from the back. In other words, from left to right in the pictures I posted in the previous post. I numbered the pins the same way, from 1 to whatever.

Here are the changes:

C1 pin 9: original goes to: IG+ for Fuel and Temp gauges, and these lamps: CEL, Windshield Washer, O/D off, Oil, Cruise, Seatbelt, Brake. New one goes to: IG+ for Fuel, speedometer, tachometer, and temp gauge. These lamps: CEL, WW, O/D, ABS, Low Gas, Brake, Seatbelt, Oil, Cruise

C2 pin 2: original goes to: C3 pin 2, Rear Defrost Lamp, odd circuit behind speedo, L and R turn signals, High beam. New one goes to: C3 pin 2, odd circuit behind speedo, L and R turn signals.

C3 pin 10: original goes to: SE on speedometer, E on fuel gauge, C4 pin 2. New goes to: C4 pin 2, C4 pin 1, SE on speedometer and fuel and tachometer

C3 pin 11: original goes to: Rear Defrost. New goes to Left Turn Lamp

C3 pin 12: original goes to: Left Turn Lamp. New goes to: high beam other leg.

C4 pin 1: original isn't connected, new is: C4 pin 2, C3 pin 10, SE on speedometer and fuel and tachometer

C4 pin 2: original is: SE on speedometer, E on Fuel Gauge, C3 pin 10. new is: C4 pin 1, C3 pin 10, SE on speedometer, fuel, tachometer.

C4 pin 9: original isn't connected, new is: TAM on tachometer

C4 pin 14: original isn't connected, new is: IG- on tachometer

C5 pin 9: original is +B on speedo, door ajar lamp, new is: +B on speedo, +B on tach, door ajar lamp

I don't think I did any damage with the incorrect cluster in. However, I'm hesitant to try it in the car again. I'm keeping my eye open for a different cluster

I'm wondering if this cluster didn't perhaps come from a different model of toyota. Does anyone know how interchangable they might be? I know the ebayer said it came from a corolla, but you never know. Of course, a different model year might explain it.

jim

I think that within the same year clusters can be different for different models, such as CE, LE, DX, etc.

 

 

I believe the odd circuit clips (there's another one between connector B and C) are some solid state relays, one of them being for lamp testing, like the CEL, charge, and oil light being on when you turn ignition to ON without starting the car.

I have a '99 factory electrical wiring diagram, let me know if you need some help; I can see what I can find in there.

Well, today my 3rd instrument cluster arrived. I'm counting the original as the 1st, and the not-quite-right one as the 2nd. This one was advertised as being for 98-00 model corollas. I must say, there is indeed a difference in the circuit between this one and the 2nd one. Exactly the difference I had listed earlier.

To be clear on this: a tach instrument cluster from a later 8th gen doesn't work correctly in the 98. This is due to the change where the rear defrost button was moved into the heating/ac control panel. I don't know which specific year this change occurred.

On the plus side, this 3rd instrument cluster came from a corolla S model I believe. The gauge faces are a greyish white, and the facia is textured instead of smooth. The lights are orange instead of green. I wasn't sure how I'd like that change, but I actually love it.

I followed the directions here.

Hopefully I'll be able to take some good pics before the end of the week.

I still have the -E error for the ambient temp, but the sensor supposedly shipped today from 1sttoyotaparts, so I should have that by this time next week.

All in all, I'm very glad I came across this thread. Thanks to everyone for their help and advice and pointers to other resources.

jim

I did something similar to that although it was the same part re-used, when I pulled out the instrument cluster for my 1994.

I messed with the odometer and caused the numbers to rotate, so I set them all back to zeros.

I also had to pull off the speed pointer and remove the faceplate.

When I put it all back together the pointer was reading 10 MPH, so I pulled it off again and turned it a little, then put it back on.

Unfortunately it is still off a little bit on the speed reading.

I would take it apart and fix it, but I sold the car.

I did tell the new owner that I set back the odometer (pretty obvious, since the car showed only 181 miles on it).

I also made a note on the title when I transferred it over to the new owner.

I wonder if the speedometer pointer has any effect on the odometer reading?

Ah, I so enjoy hacking up my gauges.

I currently have my little pig's gauges out of the car to test the twist base I bought off ebay. Those are crap and requires major hacking to fit my LED bulbs. Next time I'm buying pre-based 74 bulbs from superbrightleds.

Anyway, I found one each of 93(L)C46 EEPROM chip under both the tach and the speedo. I figure one store the temp settings - like how some tach is showing outside temp in degree F and mine showing degree C, and the other holds the readings for the odo and two trips. It'll be interesting to figure out how to hack both. default_biggrin

So it'll be interesting to know what is stored on those two chips. Too bad my homebrew willem programmer doesn't play well with these chips...

Guest JoBoo
Yup - that is the thermistor. You can double check by probing pins #8 and #16 on the wiring harness "A" - the 16 pin wire bundle that goes to the back of the cluster (it is the largest of the 4 bundles back there).

Just a sidebar Termistor question. I have a 2000 Corolla which I purchased in Rhode Island. Obviously the LCD Display shows outside temperature in terms of degrees F. I have since moved to Canada, and noticed all the displays up here show outside temperature in Degrees C.

I have been getting many mixed comments on this from many dealers, so I will ask it in here....

Can I get my LCD to read Degrees C by simply swapping the Thermistor to one marketed for the Canadian Market? or would I have to replace the Thermistor AND the console to achieve this?

I have been told I could change the sensor, another dealer told me both, and another dealer said only the console would need to be swapped.

I am confused by this because I enjoy having my speedo in MPH, but I think of Temp. in terms of degrees C.

JC

Changing the sensor may not do anything for you in this case - the thermistor is usually hooked into a bridge or a voltage divider circuit composed of high precision and stability resistors - the resulting voltage drop across the thermistor is feed into the ECM and pumped to the display. You may be able to get Toyota to change the display in the ECM or be easiest to grab a LCD display with C on it. Some cars can have the user change the metric used for temperature, but I don't remember off-hand if the Corolla did as well - it would be in the Owner's manual if it had that capability.