No Speedometer/shifting

[dksob81]

I am working ona 99 Town and Country 3.8L. The speedometer is not working, I initially thought it was a broken solder joint on the instrument panel - I have fixed prolly a dozen of these for that very issue, but the customer said she had a CHECK ENGINE light and it was not shifting, so I scanned for codes and got P0500 and P0700. So I replaced the OUTPUT SHAFT SPEED sensor and reset the code and it did not help. How can i tell what tranny it has, I think it is the 4-speed, but I am not sure. Well I replaced the output and I know from experience on other mopar product that the output and input sensors look similar, so i called my partstore and he told me if it was the 4-speed it would have both the input and output sensors (they look similar), in the other tranny (3-speed, I think) the output speed sensor gets bolted onto the tranny (does not screw in). So with that said I cannot find the input speed sensor anywhere on this tranny. Anyways do you think I just got a bad sensor or what?

[RIP]

Sounds like a classic output sensor problem. Installed a bad sensor? Good possibility especially if it's an aftermarket sensor. I've read of folks going through several to get a good one. Might try an OEM sensor. Pricier but, a bit more reliable. Try double checking the harness physically and with a meter.

I've read some shops insist on changing both the input and output sensor. I've also read about a problem with mismatched pin spacing between new sensor connectors and old sensor harness connectors on third gen vans. A 4 speed tranny shift indicator says PRND3L. Input sensor is in between the tranny cooling line connections and the output is on the far right near the shift lever shaft.

Does the speedo move on self test?

[vipergg]

The 3.8 liter has never had the 3 speed they are all the 4 speed 41TE or A604 or whatever they want to call it which is too bad because the old 3 speed was a far superior transmission to the 4 speed slush box. Looking at the factory manual it looks like it is right above the tranny solenoid pack just to the left of the output speed sensor .

[dksob81]

I got it working, I tested the NEW sensor and I got a good reading from it. then when the customer dropped the van off yesterday afternoon (they couldn't leave it the first night they had some errons to run) I checked the old sensor again and got an infinate signal, so i know for sure that sensor was bad but here was the problem why the NEW sensor wouldn't work, I notice when I unplugged the sensors that the terminals in the connector was actually coming out of the harness, so I took both terminals out thinking they might have broke but they just got unclipped some how, so I removed the retaining clip pushed the terminals back into place and put the retaining clip[ back in and tugged on the wires to make sure theyw ere secure, then put the NEW sensor in (same as before) and plugged it in and good as new, Thanks for you help tho.

[RIP]

Great news but I wonder if the reason the terminals were dislodged was because of the alignment mismatch I mentioned. That info was based on a TSB that came out several years ago.