previa speedometer

My 95 Previa speedometer stopped working and my overdrive light started flashing. I presume the latter is only indicating the former, but dont know for sure. Could this be something serious brewing? I'm stuck in a town that I want to leave tomorrow (Sunday), as I've already been stranded for days longer than I wanted to be. If I can be pretty sure itsv just the speedometer I dont care, and I will get it taken care of elsewhere. I will try to get a diagnostic code later tonight

Reply to
Joe
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The flashing overdrive light is an indication that the electronic control unit ("ECU" or computer) for the electronically controlled transmission (ECT) has detected an electrical problem with the transmission. If the transmission's speed sensor is bad or there is a problem with the wiring for the speed sensor, the ECU will start flashing the OD light. Assuming that the transmission is mechanically sound (check the transmission fluid), the van should be OK to drive although it may shift erratically.

Reply to
Ray O

I'm only getting a single flash out of the oil light, nothing out of the engine light. I've never run diagnostics on this vehicle before. Something seems goofy but I'm following the directions here that have worked in the past.http://www.off-road.com/toyota/tech/codes/

Reply to
Joe

I'm only getting a single flash out of the oil light, nothing out of the engine light. I've never run diagnostics on this vehicle before. Something seems goofy but I'm following the directions here that have worked in the past.http://www.off-road.com/toyota/tech/codes/

********* Lift the driver's seat to get access to the diagnostic terminals.

To get the diagnostic codes, short terminals TE1 and E1 with a paper clip or stiff wire. Make sure the OD switch is on and turn the ignition switch to the on position and count the flashes of the OD light (not the check engine light).

The codes are:

2 times per second - normal 4 quick flashes, a 1.5 second pause, then 2 quick flashes, then the pattern repeats - code 42 - defective speed sensor # 1 in the combination meter or related wiring

code 61 - defective speed sensor #2 in the transmission or related wiring

62, 63, and 64 - shift lock or torque converter lockup solenoids or related wiring

To cancel the codes and erase the memory, pull the 15 amp EFI/MFI fuse for

10 seconds or more.

My guess is that you will have a code 42 or 61, more likely 42.

If the oil pressure warning light is flashing or illuminated, oil pressure is low or the oil pressure sender is bad. In either case, do not run the engine until you find out the cause or the engine will be ruined if it is not already ruined.

If the oil level warning light flashes once, check the engine oil level with the dipstick under the driver's seat and check the oil level in the supplemental oil reservoir under the hood. If the oil level in the crankcase is low, oil will be pumped from the supplemental oil reservoir into the crankcase when the engine is cranking but if the supplemental reservoir is low, then the crankcase oil level will be low.

Good luck!

Reply to
Ray O

I took it for a drive this AM and it seems to drive and shift fine. Cruise isnt working though, which might point toward speed sensor too I suppose. I still get nothing but a blink of the oil light every 4-5 seconds during diagnostics.

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Reply to
Joe

I took it for a drive this AM and it seems to drive and shift fine. Cruise isnt working though, which might point toward speed sensor too I suppose. I still get nothing but a blink of the oil light every 4-5 seconds during diagnostics.

********* Is the OD button on the shifter pushed in? Are you checking with the ignition in the ON position with the engine not running? If yes to both of the above, pull the EFI/MFI fuse in the dashboard to clear the trouble codes and wait for the OD light to start flashing again.
Reply to
Ray O

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Yes, I'm doing it that way. I'll try clearing. I've been driving it for 3 days with no troubles.

How hard is it to get the sensor in/out? I dont have jack stands with me and I havent crawled under to look for it though I can probably get close because it has pretty good clearance. I havent found anyone who isnt a crook yet to replace it for me, since I'm on the road for a few weeks.

Reply to
Joe

Yes, I'm doing it that way. I'll try clearing. I've been driving it for 3 days with no troubles.

How hard is it to get the sensor in/out? I dont have jack stands with me and I havent crawled under to look for it though I can probably get close because it has pretty good clearance. I havent found anyone who isnt a crook yet to replace it for me, since I'm on the road for a few weeks.

************ Speed sensor #1 for the speedometer is located behind the speedometer. To get at it, you have to remove the steering column cover, then pop the black trim above the instrument cluster off, remove 4 screws, remove the cable for the shift lever, pull the cluster towards you a little and disconnect all of the wiring connectors and the speedometer cable. To check the sensor, connect a positive 12 V source to the right hand terminal on the speed sensor, along with the positive lead from a volt meter. Connect the negative lead from the battery to the middle terminal and the negative lead from the volt meter to the left hand terminal. Turn the shaft on the speed sensor by hand and check that the voltage changes from battery positive voltage to less than to volts four times per each revolution of the speed sensor shaft. If operation is not as specified, replace the sensor.

You need a set of jack stands to check speed sensor #2 on the transmission because you have to be able to rotate the rear wheels while checking the sensor.

Reply to
Ray O

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awright, thanks. Sounds like more than I want to get into on qa camping trip. I'll just drive it for now, and try the diagnostics again one of these days till I get back to a trusted mechanic.

Reply to
Joe

awright, thanks. Sounds like more than I want to get into on qa camping trip. I'll just drive it for now, and try the diagnostics again one of these days till I get back to a trusted mechanic.

******** Enjoy your camping trip! I've camped many nights using our old Previa.
Reply to
Ray O

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Finally getting back to this...

I cleared the memory and then drove it till I got the flashing OD light again. With the OD turned on, I jumped the E1 and TE1 terminals just like before and turned the key to the ON position. I got the exact same result: a single flash from the check oil light, and nothing more.

Reply to
Joe

Finally getting back to this...

I cleared the memory and then drove it till I got the flashing OD light again. With the OD turned on, I jumped the E1 and TE1 terminals just like before and turned the key to the ON position. I got the exact same result: a single flash from the check oil light, and nothing more.

************* Sorry, It just dawned on me that the '95 Previa implemented the On Board Diagnostics Generation II (OBD II) protocol, which uses a different procedure for pulling trouble codes.

Somewhere under the driver's side of the dashboard will be an OBD II connector shaped like the one on this page:

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You will need an OBD II code scanner to pull trouble codes. Many auto repair places like AutoZone will let you borrow the scanner to pull codes for free. Write down the trouble codes - the format will be something like P0###, clear the codes, and post the codes here.

I apologize for the confustion.

Reply to
Ray O

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.com...

I'll get right on it. Thanks.

Reply to
Joe

I'll get right on it. Thanks.

******** You're welcome, sorry again about the mixup.
Reply to
Ray O

Not a problem! I appreciate all your help on the group.

Reply to
Joe

Code was either p0401 or p0500...I'm too lazy to run out to the car where its written down, but one was egr and the pertinent one was Vehicle Speed Sensor with 3 choices

1) short 2) bad connection 3) VSS

A whole slew of parts came up for speed sensor when he typed that in for this vehicle, tranny sensor, wheel speed sensor, and others. But of past luck is my guide, the VSS itself was the $349 part....

Reply to
Joe

Code was either p0401 or p0500...I'm too lazy to run out to the car where its written down, but one was egr and the pertinent one was Vehicle Speed Sensor with 3 choices

1) short 2) bad connection 3) VSS

A whole slew of parts came up for speed sensor when he typed that in for this vehicle, tranny sensor, wheel speed sensor, and others. But of past luck is my guide, the VSS itself was the $349 part....

***************** P0401 is EGR flow insufficient detected. This can be caused, in order of likelihood, by an EGR valve that is clogged;, a manifold vacuum leak; or a problem with the EGR position sensor. Based on the age of the vehicle, I'd check the EGR sensor by unplugging the vacuum hoses from the EGR modulator, plugging the hoses with a golf tee, and then applying vacuum directly to the modulator with the engine idling. If the EGR valve is opening, the engine should start to run roughly and start to die. If the engine doesn't want to die when vacuum is applied directly to the EGR modulator, the EGR valve may be clogged. It would probably need replacement if this were the case, but you might save some money by removing the EGR valve and digging the carbon buildup from the inside with a screwdriver or awl. Worst case, you still need a new EGR valve. Best case, you got some more time and miles out of the valve.

P0500 is vehicle speed sensor malfunction. The list you posed is accurate.

good luck!

Reply to
Ray O

So is this VSS the behind-instrument cluster sensor then?

Reply to
Joe

So is this VSS the behind-instrument cluster sensor then?

******** I think that there are 2 VSS, in the transmission and 1 behind the instrument cluster. Since the speedo and cruise are inoperative, I'd check the instrument cluster sensor first. It is also the easier one to check.
Reply to
Ray O

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Wouldn't there be a separate diagnostic code for Transmission Speed Sensor? The parts store pulled up both for this vehicle (TSS and VSS) but the OBD clearly said VSS. I dont want to read too much into that fact though.

Reply to
Joe

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