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2000 GT 4V swapped, no spedometer since swap

1525 Views 4 Replies 3 Participants Last post by  Djreibert2
Hey guys, so 6 months or so ago I bought a 80,000 mile 4V from a wrecked 99 cobra to swap into my 2000 GT. Love the 4V power, it runs great! For the swap I swapped in the motor, ecu, and wire harness from the Cobra into my GT. Turned PATS off through custom email tune. Kept my T45 from my GT and bolted it right up to the 4V. My problem is, ever since the swap, my spedometer has not worked. Everything else on the dash works perfect (rpm tach, temp, fuel, etc...)

Things I have tried to fix it that have not worked-
Replaced speed sensor in trans
Checked fuses
Replaced alternator (returned it after it didnt solve issue)
Installed a 99 cobra gauge cluster (cobras have 160 speedo vs. GT 150 speedo, thought there might be a calibration issue)

Like i said, it worked perfectly before the motor swap. My next thought is to take it to a dealership to have them take a look at it. Any other ideas before I take it to the stealership???

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There's an instrument cluster diagnostic built in to these clusters that may be helpful. I forget the exact procedure but basically just involves hitting the trip odometer button - search here or Google for instructions on how to activate and use the diagnostic feature.

Anyway, it will display various analog cluster readings (rpm, speedo etc) in the odometer display. It would be helpful to know if the cluster is getting a speed signal from the pcm, and this test should clarify that. If you get a speedo reading in the display then there is likely fault with the cluster, such as a bad stepper motor.

Something else that may be worth trying is swapping the original cluster back in, see if anything's different.
Thanks for the response! and yes, I have tried different clusters. Neither of them have worked. I do not believe it is a faulty stepper motor. However I will try the ODO speedo readout. However, I am not sure I will get a speed readout for that either, because my odometer has not been counting either (due to there being no speedo). I would think that the odo would still work if there was a speed reading in the diagnostic feature
Does your hand held turner allow for monitoring of operational PID's? If so, it would be a HUGE help to monitor what the PCM "thinks" the car's speed is.

Why is this important? Because on the 99+, the PCM "tells" the cluster what to display. If the speed is correct in the PCM, then we need to look for a break down between the PCM and cluster.

If the car's speed is wrong (or zero) in the PCM, then we need to look for a break down between the PCM and the OSS sensor.

There are differences in the wiring between the Cobra and GT. This may be a result of mix and matching. Or may be not related at all.
Last night i checked the ODO readout for the speed. I had no speed reading... And I have the SF3/X3 tuner. So at this point I believe it is something between the PCM and the Cluster. Maybe something is messed up in the Cobra wire harness I swapped in the car
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