Sensors or cluster? Vehicle Speed Sensor A -- P0500

I've had an P0500 code for a little over two years now with no noticeable effects, sometimes the check engine light is on, sometimes not. Just recently my automatic 4.0 is very occasionally stalling when coming to a stop (while still slowing down, not idling). All electronics stay on.

I don't know if the P0500 is related, but its the only code I'm getting so I figured I'd start there. When the check engine light is on, the ecu isn't getting any speed data but the speedometer and all 4 wheel speed sensors still work fine, so I'm guessing its something to do with the sensors near the transmission.

Because it is an intermittent issue, could it be bad sensors or is it more likely a wiring/instrument cluster issue. I know the instrument cluster tends to go bad from time to time on 2nd gen tacos.

I took it to a shop and they recommended replacing the sensors then see if that fixes it or not. While they had it, they said the transmission sensors didn't work at all but they were working fine on my drive home (no light and code reader had input). I know the only way to know the cause for sure is to scope test, which they didn't do, but just wanted to see what anyone else thinks before I move forward with just swapping the sensors.

Thanks in advance for any advice/input.

 

If you speedometer always works it's likely the cluster, next time it does it give the cluster a few taps and see if your vehicle speed comes back in engine data. If it does then it's in the cluster.

It seems to be a relatively common failure in 05-11 trucks, not as common on 12-15s

We have figured out the SPD circuit in the cluster can be bypassed to avoid having to replace it, see the thread below.
https://www.tacomaworld.com/threads/clear-a-single-code-to-pass-inspection.802680/

The shop was apparently not reading service info, there is no vehicle speed sensor on 2nd gen automatic trucks. Only 05-11 manual transmission trucks use a vehicle speed sensor but the rest of the SPD circuit is the same.
See the post below for a full description of the vehicle speed circuit and how it works.
https://www.tacomaworld.com/threads/2nd-gen-information-diagnostics.784008/#post-28042157

 

a speed sensor failure can be intermittent, and is probably cheaper and easier to replace than a cluster.

"my vehicle is older than 10y and 100k, is part x worn?"
Yes.

 

2nd gen automatic trucks do not have a Vehicle Speed Sensor (see my post above), they use the rear wheel speed sensors via the ABS module which transmits vehicle speed to the Combination Meter (Instrument Cluster) which transmits it to all other modules. OP said speedometer and all 4 wheel speed sensors always work and no ABS light is on therefore it can't be an issue with the speed sensors.

Straight from the FSM.

DESCRIPTION:

Automatic Transaxle Models: Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle speed using the skid control ECU and wheel speed sensor. The wheel speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4- pulse signal and transmits it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of the pulse signal.

 

Thanks for the solid reply, super helpful and i'll try that bypass. So just for clarification, the sensors on the transmission are pretty much just for shifting?

 

Correct.
You would get a P0717 (Input Speed Sensor No Signal) or P0722 (Output Speed Sensor No Signal) for those.

 

My 2021 Tacoma TRD Sport manual trans with 21,860 miles throws the P0500 code. I clear the code but comes back after 63 miles...clear again comes back after 63 mi. Might be covered under warranty? My dealer is 2.5 hours away, so I fix most problems myself. No other problems, notice no change.

Randy

 

I haven't researched how the Vehicle Speed system works on 3rd gens but you should still be under the 3/36 bumper to bumper warranty.

 

My 36 mo was up Jan 13

 

It may be covered under powertrain but idk.