Overdrive stoped working / Flashing O/D off light

2002 Windstar 180k miles

I had the typical engine light on - did the isolator grommet fix, and DPFE sensor replacement which fixed the engine light (after 4 years of it being on, lol).

I have an intermittant ABS/Brake light on but the recall wiring harness has been performed - no improvement on the intermittant ABS light but I'm not concerned about that right now.

What I am concerned with is the O/D. The O/D off light started flashing intermittantly, some time ago ( 6 months, a year, who knows). Now pretty much every time we drive it for any length of time the light starts flashing. The trans seems to shift just fine up and down, except when its supposed to shift into O/D.

My wife and I have been been turning off the O/D with the switch on the shifter handle as soon as we start the van for the past 3 days and the O/D off light has not flashed at all (about 100 miles now). Driving about 75 mph, there does seem to be a little, tiny, studder but I can't tell if that's just the adaptive stuff tuning itself, if its trans related, or otherwise - it's too subtle for me to be able to tell. I'm not sure what to try to replace first.

I've read many other posts, on many message boards, but nobodys description quite matches the problem I am seeing.

Any suggestions? (no engine codes left, have not had ABS codes or trans codes read)

Thanks!

A flashing O/D light is like a Check Engine Light for the transmission.
There should be a code stored....as the flashing light is an indication of a problem having been detected.
I would invest in a diagnostic from a trusted shop.
It could be something as simple as a Transmission Range Sensor (TRS), aka Neutral Safety switch......or more expensive.

Thanks for the reply.

I was hoping to try a cheap fix or two before spending more than $100 on a diag. read.

If it sounds like the TRS is a resonable thing to replace, I'm all for it - it's easy and cheap to replace. If someone thinks there is something else that is more likely causing the problem, than I'm willing to try that too.

This is the fourth day in a row now that the O/D off light has not flashed - we've been turning off the O/D as soon as we start the engine.

One other bit to add, and I don't know if it's related or not, but the RPM's have slowly been creaping up over the years. Right before the O/D stopped working, at about 75 MPH the RPM's would be at about 3400.

Thanks again for the help!

On my 99, at 90k miles the tranny pump shaft snapped .... no go ... Tranny repaired for $1700 by dealer.

Later, at 200k miles, I had similar symptoms to yours .. invested about $200 in sensors and pressure regulators(wasted money) ... no good, still no top gear after driving a few miles. Had code read ... "too much slippage detected in final drive clutch" ... tranny continued to worsen over time. I finally coughed up $1700 for Ford replacement ... it had all new sensors and stuff, ... I installed tranny myself. Turned out to be a good deal ... nearly 100k miles on replacement now.

If the OD is off, drive only in city limits.
I had a VSS go bad causing that same symptom.

ABS - Check brake fluid, because worn brakes use more fluid.

The VSS might be causing the problem with the ABS alarm.

If a Windstar has wheel speed sensors, make sure the sensors and connectors are cleand with CRC Electronic cleaner.

Thanks for the help and suggestions so far! I'll see what kind of time I'll have this weekend - I might take a stab at the VSS sensor and try to find the ABS sensors.

You might try shopping for a "friendly" service writer/shop supervisor at some Ford dealership ... if you have a dealership nearby. I am lucky enough to have a few dealerships in driving distance around. In one of them, I have found a helpful management person who will take the hand held scanner out to the parking lot and scan my drivetrain in two minutes ... for this he gets a returning custormer to his parts counter ... and occassionally, to the service department.

Even if you have to pay a few bucks (shop beforehand) for the scan ... you will know what you are facing for sure.

I am doubtful that the ABS system will fault the OD.

You might try shopping for a "friendly" service writer/shop supervisor at some Ford dealership ... if you have a dealership nearby. I am lucky enough to have a few dealerships in driving distance around. In one of them, I have found a helpful management person who will take the hand held scanner out to the parking lot and scan my drivetrain in two minutes ... for this he gets a returning custormer to his parts counter ... and occassionally, to the service department.

Even if you have to pay a few bucks (shop beforehand) for the scan ... you will know what you are facing for sure.

I am doubtful that the ABS system will fault the OD.


Good point! There are several dealerships around here.

ABS - Check brake fluid, because worn brakes use more fluid.

The VSS might be causing the problem with the ABS alarm.




That is interesting. I just realized today that after a week of turning off the O/D as soon as we start the car, we have not seen the ABS light come on since.

We've put about 200 miles on it so far (and the check engine light has not come back on either).

Of course I just read the procedure for replacing the VSS and it doesn't sound fun, lol.

So the VSS sensor that you guys are talking about - are you referring to the magnetic one, or the TSS input sensor that goes into the top of the transaxle housing that's a pain to get to?

Thanks again!

PS I replaced the TR sensor because they had it in stock at Autozone today - no change.

Vehicle Speed Sensor is the one that your speedometer cable connects to (If you have the mechanical speedometer).
That is the one that is hard to get to.......you have to go by feel.
It is above a catalytic converter, so you have to let that cool down before working.
The speedometer cable is in 2 parts (at least on my '96), the connection is below the flex hose that goes from the air filter box to the throttle body.


The Turbin Shaft Sensor, TSS, is located on the driver's side end of the transaxle.....near where the driver's side shaft comes out.
It measures the speed of the shaft that comes out of the torque converter and goes into the gear select part of the transmission........often called "Intermediate" shaft.

At this point.....I would recommend trying to read the codes, the VSS and TSS should trigger a code if they are defective.
It can get expensive pretty fast changing parts and not have them be the problem.
It is also possible.....though I hope not.....that the problem will be internal to the transmission and be expensive to have repaired, the sooner you find out, the better.

ABS sensors..... At the end of each shaft going to each wheel.....you will find a "Gear".
That gear is the exciter ring.......and you will find the sensor located next to that.
The each time a "tooth" of the gear passes the sensor, it creates a magnetic pulse.....which the sensor turns into a electrical signal.
The computer measures the pulses from each wheel sensor to determine how fast each wheel is turning as compared to the other wheels......then the ABS system can determine if one or more wheels are in a skid.....and pulse the brake for that wheel.
Here is a link to a picture of the front suspension on my '96 Windstar that shows the ABS sensor and exciter ring. http://rides.webshots.com/photo/2030899680011220610romxdY

The VSS is used for both ABS data, and OD, the ECU will tell the transmission when to shift into OD.

The VSS is used for both ABS data, and OD, the ECU will tell the transmission when to shift into OD.


Does anybody have a part number for this? 2002 - Windstar again. At Autozone, their VSS is a magnetic pickup sensor which I don't believe is correct.

I looked the Vehicle speed sensor up for the 2002 windstar on AutoZone's website.....Under "Engine Management" Duralast # SU1283
I compare it to the one shown on AdvanceAutoparts website ...Under "Replacement parts.....Sensors" ..and the one on advance has a lead that goes from the sensor to the connector .
On RockAuto's website, they list 2 speed sensors.....Under "Electrical.....Sensors.....Speed sensor".....1 is "input" and the other is "output".
Output side is the one with the lead, input side does not have a lead.....but the connector on the "input side" sensor is at a right angle, vs the autozone one being straight.
Maybe you could look at the sensor that is located near the output shaft on the driver's side and see which one it looks like.
The one that is known as the "Vehicle Speed Sensor" is the one that is NOT next to the output shaft on the driver's side......it is located on the back side of the transmission......above a catalytic converter.
Neither one look like the one that I had on my '96 windstar.....I just looked this part up for the 1996 windstar, and the part that I get on all the listed websites is much different.....has a shaft with a gear on it......so I am guessing they changed the design between '96 and your model year.
On Rockauto's website, the OUTPUT SIDE one is the one that matches my VSS, that my mechanical speedometer cable connects to.
The Input side looks much different.

I looked the Vehicle speed sensor up for the 2002 windstar on AutoZone's website.....Under "Engine Management" Duralast # SU1283
I compare it to the one shown on AdvanceAutoparts website ...Under "Replacement parts.....Sensors" ..and the one on advance has a lead that goes from the sensor to the connector .
On RockAuto's website, they list 2 speed sensors.....Under "Electrical.....Sensors.....Speed sensor".....1 is "input" and the other is "output".
Output side is the one with the lead, input side does not have a lead.....but the connector on the "input side" sensor is at a right angle, vs the autozone one being straight.
Maybe you could look at the sensor that is located near the output shaft on the driver's side and see which one it looks like.
The one that is known as the "Vehicle Speed Sensor" is the one that is NOT next to the output shaft on the driver's side......it is located on the back side of the transmission......above a catalytic converter.
Neither one look like the one that I had on my '96 windstar.....I just looked this part up for the 1996 windstar, and the part that I get on all the listed websites is much different.....has a shaft with a gear on it......so I am guessing they changed the design between '96 and your model year.
On Rockauto's website, the OUTPUT SIDE one is the one that matches my VSS, that my mechanical speedometer cable connects to.
The Input side looks much different.


Yes, it seems to be very confusing. The Hayes manual shows a picture of the sensor with the gear on it and says to save the old gear and put it on the new sensor - but the instructions don't say for which year that procedure is for.

I hate to take it out just so that I can bring it in to the store because I believe the O-ring will have to be replaced and if they don't have one in stock, I'm out of a van for a few days. Maybe the dealer will know better - but I doubt it.

Flashing O/D light indicates that a transmission error occured, and a code has been stored. I think most code readers will be able to retrieve any transmission codes, so it can be read at no charge at a auto parts store that offers the service.

My transmission does a shutter, itermittently due to the torque converter cluth. It's been an on going problem that no professional mechanic has been able to resolve. I am currently considering a Ford remanufactured transmission, but in the mean time it works well enough.

However, when driving through mountainous terrian for long periods at high speeds, the TCC engages/disengages often enough that eventually I'll get the flash. Usually the code stored is P0741 (torque converter clutch circuit performance or stuck off).

I would try to have the codes read at a parts store that does this at no charge.