Curb Hop

Hi, This is my first question to post on here thanks in advance for any help you guys can offer. I have a 98 XJ SE 2WD.. Code p0500 and my speedo stays at zero. I have removed the cluster to check connections for corrosion and there is no corrosion. I checked the connectors going into the firewall and they seem to be secure as well. I changed out the larger sensor.. 55 bucks at advance auto.. and still no dice. Now I have ordered one of the other smaller sensors from rock auto. Hopefully it will be here today or tommorow. $87 bucks (it is 115ish at the parts stores) Does anyone have any experience with this code on a 98. I read a previous thread on this subject on a 97 XJ and apparently those only have 2 speed sensors. My plan now is to change out one of them and check it. If that doesnt work maybe put the old one back in and put the new one in the other slot?
If anyone has experience with this speak up :-) Thanks.

CCKen

Are we talking about the Vehicle Speed Sensor (VSS) that gives speedometer signals or Transmission Speed Sensors?

The '98 have one VSS and two Transmission Speed Sensors.

What sensors are you talking about? "Larger Sensor - Smaller Sensor"?

If you are talking bout the VSS on the 2WD extension housing, it has a Speedometer Adaptor and a Vehicle Speed Sensor mounted on it (with an electrical connector on it). Are these the Larger and Smaller sensors you re talking about?

The Vehicle Speed Sensor is the device that sends signals to the PCM concerning vehicle speed, and which the PCM turns into signals to the Speedometer. P0500 is A vehicle speed sensor signal was not detected. A defective Vehicle Speed Sensor, or a bad connection at the sensor, would cause this. Vehicle Speed Sensors have a habit of failing.

Curb Hop

The sensor I changed must be the VSS. It is slightly larger than the other two. The
"other two" appear to be identical from the outside but I have not removed them yet. I ordered one from RockAuto. I know how to turn a wrench but am no expert at understanding what the parts I am replacing are actually doing. The plug on the VSS i changed appeared to be fine. was not corroded or anything. I borrowed an ohm meter from work but have not used it yet because I really don't know how anyway. :/ Does that answer you question?

Curb Hop

I just re-read your reply.. are you saying that the 2 transmission speed sensors have nothing to do with the speedometer? Also i did not note.. Automatic transmission is shifting a little late. Not too bad but before the engine light came on with the p0500 it was very smooth.. now it seems to rev a little to high before it shifts.

CCKen

The transmission shifting problem may just need the kick down cable adjusted.

Here's some possible causes for P0500:

5 VOLT SUPPLY CIRCUIT OPEN
SENSOR GROUND CIRCUIT OPEN
VEHICLE SPEED SIGNAL CIRCUIT OPEN
VEHICLE SPEED SIGNAL CIRCUIT SHORTED TO GROUND
VEHICLE SPEED SIGNAL CIRCUIT SHORTED TO VOLTAGE
POWERTRAIN CONTROL MODULE (VEHICLE SPEED SENSOR)

TEST ACTION APPLICABILITY

Curb Hop

Ok, So how do I test those theories? Ohm reader? If so, how do I know what readings are good and bad?

CCKen

Does this look like the VSS you changed?

Curb Hop

That would be it.. (figure A in the diagram) I wonder if the speedometer adapter can be changed? I'll have to look at it again. When I changed it I thought it was going into the transmission.

Curb Hop

So the transmission speed sensor came in from rock auto yesterday. Now I'm not sure I should even try to put it in? Anyone else have any experience here? I changed the vehicle speed sensor.. the plug is good and clean. Still getting code p0500

CCKen

You should pull the adaptor out and see if the gear is corn cobbed.

If the gear is okay, try the instrument cluster actuator test. This will let you know if the speedometer itself is bad or there is a problem in the wiring from the PCM to the VSS.

The PCM drives the instruments through the CCD Data Bus. There's a two wire CCD Bus circuit that goes from the PCM to the instrument cluster. If every instrument works okay during the test it can be assumed that the CCD Bus circuit is intact and all instruments are in working order.

The test:

Instrument Cluster Actuator Test

(1) Begin the test with the ignition switch in the Off position.

(2) Depress the trip odometer reset button.

(3) While holding the trip odometer reset button depressed, turn the ignition switch to the On position, but do not start the engine.

(4) Release the trip odometer reset button.

(5) The gauges should cycle through their ranges, stopping at intermediate readings, going up and going down, at two second intervals. The indicator lamps should cycle on and off.

(6) The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test, if the ignition switch is turned to the Off position during the test, or if a vehicle speed message indicating that the vehicle is moving is received from the PCM on the CCD data bus during the test.

Curb Hop

Ok. I'll check it out first thing in the morning. If the gear is screwed up what is the name of the part that I need to replace? Speedo adapter doesn't come up on advance or oreilly. I haven't tried the other parts sites yet but not sure what the part is called.

Curb Hop

Oh and I did the cluster test everything was good there

CCKen

Morris 4X4 has gears.

http://www.jeep4x4center.com/jeep-sp...ears/index.htm

Curb Hop

Well I pulled it out.. the gear on the adapter is fine but there is a yellow piece that resembles half a hampster wheel.. its like a gear on outside and filter on the inside.. I have pictures but not sure how to post them on here. I'll try to figure that out.

Curb Hop

https://www.cherokeeforum.com/attach...1&d=1362166972

https://www.cherokeeforum.com/attach...1&d=1362166972