Odometer not working

Just been out in the car this morning and noticed the odometer is not moving at all. The speedo is fine but the odometer and trip don't do anything. Is this a common problem?

I've the same problem with mine, haven't addressed it yet.

Probably the buffer circuit in the odometer circuit board has given up, or has some dry solders.

I would also expect your orange engine MIL light to be lit up once you've got the car up to temperature and speed (50mph+). If it isn't, check that it comes on when you have the ignition at the II position. The point is that the odo not counting up should generate a MIL error that can be safely ignored, BUT you need that MIL light working in case something bad ever does happen.

I didn't notice any lights when driving, I've just tried the ignition at the second position and no orange lights came on.

I didn't notice any lights when driving, I've just tried the ignition at the second position and no orange lights came on.

OK. Actually, it might not be a buffer circuit issue with the odo PCB. It might just be dry solders, or some other issue with the odo.

Anyway, you have 2 issues: your odo doesn't count up, and your MIL light doesn't work. Both could be caused by dry solders, quite common problem on these cars.

Just to update this I took the car to my local Toyota dealer and they did a code read but they couldn't find any fault codes. They suggested replacing the speedo cluster but they couldn't get one until February.

I'm guessing since there is no fault codes that there is an internal problem with the odometer? If it is faulty how do you replace it to read the correct mileage?

Assuming the garage is competent and there genuinely aren't any fault codes logged, it does sound like an internal fault with the odo. Very unusual though for these issues not to trigger code 42 (speed sensor error). Here's why:

The speed sensor's on the gearbox. The signal from it goes to the speedo cluster. The cluster uses it to, well, show the speed. The speedo cluster then outputs the signal to the odo. The odo uses it to count up the display, buffers it, and re-outputs the signal to the ECU.

If the ECU doesn't see a speed signal once the engine's up to temperature and the car's travelling at at least 50mph (I think it uses the other speed sensor to tell what the speed is. Sounds like a circular argument, the details of which I don't know about!), then the ECU logs a code 42 error.

The point is, the gearbox speed sensor, speedo cluster, odo and finally the ECU are in a daisy chain. If you break the chain anywhere, the ECU won't see the signal and will log the error.

Common failure points:

1) Failure of an aftermarket speedo converter spliced into the daisy chain somewhere

2) Failure of the odo's buffer circuit, meaning it doesn't re-output the signal to the ECU

I think you've got one of the following scenarios:

1) your car hasn't been above 50mph when warm since you last reset the ECU/removed the battery. This means that the ECU won't have met all the conditions to log the expected error. Your odo problem is probably (and it is just an educated guess) caused by a faulty odo unit.

2) your car has been above 50mph when warm, and still hasn't logged any errors. This means each component in the daisy chain is doing its job of receiving the signal and re-outputting it, but that the numbers just aren't counting up.

Both 1 and 2 suggest a new odo is required, not a new speedo cluster.

Mine was a simple wire fault on the odo is didnt fault the system at all

So if the odometer is faulty, how does one change it? Can you alter the mileage on the new odometer to match what it should be?

Hi

I had the same fault and was caused by dry joints on the odo unit. This was repaired after re-soldering all the joints on the dod unit

Snuff

So if the odometer is faulty, how does one change it? Can you alter the mileage on the new odometer to match what it should be?

You either need the electronics knowledge, or get someone to do it for you. They need to pulse the input of the new odo so that the numbers count up.

Just been out in the car this morning and noticed the odometer is not moving at all. The speedo is fine but the odometer and trip don't do anything. Is this a common problem?

Apparently it is with cars from High Wycombe.

I'll need to check some of these issues as well as mine isn't working..

I was having a traction control issue a while back and I think whenever I got the car back from SSI, it wasn't working. He mentioned something to do with a buffer, I think he may have bypassed it if that's possible. Anyone experienced this?

I'll need to check some of these issues as well as mine isn't working..

 

I was having a traction control issue a while back and I think whenever I got the car back from SSI, it wasn't working. He mentioned something to do with a buffer, I think he may have bypassed it if that's possible. Anyone experienced this?

Bypassing the odo's buffer is often used as a fix for the code 42 warning lights, assuming the fault is in the buffer circuit.

Bypassing the odo's buffer is often used as a fix for the code 42 warning lights, assuming the fault is in the buffer circuit.

Is there any way round it getting it working again whilst eliminating the code42 warning lights? If I was advised of the odo not working to fix it I'd have said no!

Bypassing its buffer doesn't stop the odo from working. I've run a bypassed buffer for 6+ years, and my odo counts up with no ill effects. The Thor speed converter happens to bypass the buffer. It sounds like your odo has several faults, or it isn't getting the input speed signal. Check the wire from speedo to odo for ropey splices (if you're running any aftermarket converter etc), loose wire, etc.

My odo reset itself to zero. no idea why.

Sell it now for 60k

Bypassing its buffer doesn't stop the odo from working. I've run a bypassed buffer for 6+ years, and my odo counts up with no ill effects. The Thor speed converter happens to bypass the buffer. It sounds like your odo has several faults, or it isn't getting the input speed signal. Check the wire from speedo to odo for ropey splices (if you're running any aftermarket converter etc), loose wire, etc.

I'll check that dude, cheers. If theres nothing wrong is it the case of buying a new 2nd hand unit? Is there any way to correct mileage or know anyone who can?

I'll check that dude, cheers. If theres nothing wrong is it the case of buying a new 2nd hand unit?

Probably. Eliminate the other probable causes of the fault that I've described in this thread first.

Is there any way to correct mileage or know anyone who can?

Post #11 on this thread

Mine does an odd thing aswell, racks up in km but the trip resets every time I turn off the ignition. Not a major issues just would like to know if anyone has any thoughts of what would cause this?

I think steve..b is on it, good guy to have on the club. I had this problem and changing the delimiter / KPH to MPH unit resolved it.

We are all lucky the old Supras are relatively speaking, "old tech", I also think a good "mapper" is not common and so important to optimmise performance.

I was involved in FMEA (failure mode effect analysis) and we always saw fault codes as a guide, in that they sort of point you to a certain area of the control system, but 90% of the time you end up changing bits until the actual fault is isolated. The problem being you may not have the bits and may not know if they are not faulty, it can be a "mine field" even for the professionals. This club is good as it can bring out many member's experiences where 90% of he time the fault becomes well established. Good luck anyway, these are really frustrating faults, i have had my share. Herbie.

Just to update this, I have had the dash out to check the wiring behind the instruments, and there is a black box in the wiring for the speed conversion, and there didn't seem to be anything wrong with any of the connections.

Manually moving the gears did cause the trip to move, but the odometer was stuck and wouldn't roll over, so it seems as though it is a mechanical failure of the odometer, not an electronics issue.

So you have a VVTi with the mechanical odometer and trip readout? The earlier cars were electronic digital displays..

Yes the odo/trip are mechanical, it's not on an electronic display.