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Discussion Starter #1
ok this is on my friends 94 concorde 3.5.
in park with the engine idling,the speedo shows approx 70 mph. if you rev the engine the speedo will go up like the tach. when driving,you are limited to about 30 mph because the speed limiter kicks in (speedo showing between 110 and 115,but actually going about 30 mph)
the output speed sensor has been replaced,but nothing else. if you disconnect either the input or output sensors then the speedo won't work(of course the trans will go in limp mode,so can't drive like that)
could this be a problem with the tcm? any input would be greatly appreciated(diagrams,etc.) btw,i'm new here. great site!
 

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Maybe some of this will help you :

Vehicle Speed Sensor

OPERATION

The vehicle speed sensor supplies the vehicle speed and distance inputs to the PCM. The speed sensor is located in the transaxle extension housing to sense vehicle motion.

The speed and distance signals, along with a closed throttle signal from the TPS, determine if a closed throttle deceleration or normal idle condition (vehicle stopped) exists. Under deceleration conditions, the PCM adjusts the idle air control motor to maintain a desired MAP value. Under idle conditions, the PCM adjusts the idle air control motor to maintain a desired engine speed.



TESTING

See Figures 1, 2 and 3


Fig. 1: Wiring schematic for the vehicle speed sensor-1993-95 models




Fig. 2: Wiring schematic for the vehicle speed sensor-1996-97 models




Fig. 3: PCM and TCM pin terminal ID for the vehicle speed sensor



Before testing any electrical component, inspect the wiring and connectors for damage. Also wiggle the connectors to ensure a that they are firmly engaged.

Unplug the vehicle speed sensor wiring connector.

Turn the ignition ON.

Using a voltmeter, measure the voltage from the cavity 58 (white/orange) wire with the terminal of the wiring harness connector to a good ground. Refer to the accompanying wiring illustration. The power supplied to the sensor should be at least 4.0 volts; if it is not, then a problem lies with the circuit, the transaxle control module or the PCM. These systems should be inspected before proceeding with this test.

Connect an ohmmeter between the speed sensor signal circuit and check for resistance.

If the resistance is above 5.0 ohms, there is an open in the speed sensor signal circuit which must be repaired.

If the resistance is below 5.0 ohms. Use an ohmmeter probe cavity 47 (1993-95) and 66 (1996-97) of the PCM connector. See the accompanying illustrations. There is a short to ground in the speed sensor circuit.

If not, replace the PCM.



REMOVAL & INSTALLATION



Input Sensor

See Figure 4


Fig. 4: Exploded view of the vehicle speed sensors located on the side of the transaxles



When the vehicle speed sensor is removed for any reason, a new O-ring must be installed on its outside diameter. The input and output speed sensors are NOT interchangeable.

The input speed sensor is located on the left side of the transaxle case.

Raise and support the front of the vehicle safely on jackstands.

Unplug the harness connector from the sensor. Make sure that the weatherseal stays on the harness connector.

Unscrew the sensor from the transaxle.

Place a pan under the sensor to catch any transaxle fluid which may leak out of the sensor mounting hole (not much, if any, will leak out unless the vehicle is now moved).

Carefully pull the sensor out of the transaxle case.

To install:

Install a new O-ring to the sensor.

Carefully thread the sensor back into the transaxle housing.

Tighten the sensor to 180-300 inch lbs. (20-34 Nm).

Plug the sensor connector back into the wiring harness.

Lower the vehicle.



Output Sensor

When the vehicle speed sensor is removed for any reason, a new O-ring must be installed on its outside diameter. The input and output speed sensors are NOT interchangeable.

The output speed sensor is located on the left side of the transaxle case.

Raise and support the front of the vehicle safely on jackstands.

Unplug the harness connector from the sensor. Make sure that the weatherseal stays on the harness connector.

Unscrew the sensor from the transaxle.

Place a pan under the sensor to catch any transaxle fluid which may leak out of the sensor mounting hole (not much, if any, will leak out unless the vehicle is now moved).

Carefully pull the sensor out of the transaxle case.

To install:

Install a new O-ring to the sensor.

Carefully thread the sensor back into the transaxle housing.

Tighten the sensor to 180-300 inch lbs. (20-34 Nm).

Plug the sensor connector back into the wiring harness.

Lower the vehicle.
 

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Discussion Starter #5
that helps some.thanks! has anyone else ever had this problem? i was a dodge tech for about 5 years and never saw this. i have replaced a lot of tcm's and i/o speed sensors,but there either was an issue with the trans or the speedo was completely inop. of course my mainstay was 96 and newer obd2. the trans shifts fine on this one and no check engine light either.
 

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Discussion Starter #7
ok, i now know that it's not the cluster. disconnected the cluster,test drove,same shutting off problem. it did seem to clear up and gain speed once,but then started back being possesed. seems to be a partially broken/shorted wire .yippie!!!!!! does anyone know if the speed signal goes from the pcm directly to the cluster or if it passes through the bcm first? i know the signal wire changes colors from oss-tcm-pcm-????-cluster. surely someone has a good speedo wiring schematic!!!! help please.
 

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warlockpain said:
ok, i now know that it's not the cluster. disconnected the cluster,test drove,same shutting off problem. it did seem to clear up and gain speed once,but then started back being possesed. seems to be a partially broken/shorted wire .yippie!!!!!! does anyone know if the speed signal goes from the pcm directly to the cluster or if it passes through the bcm first? i know the signal wire changes colors from oss-tcm-pcm-????-cluster. surely someone has a good speedo wiring schematic!!!! help please.
Well, if nobody can get you one by tommorow, I'll get you the schematic that you need tomorrow. Can't get into the computer that has it until then.
 

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Discussion Starter #9
you wouldn't happen to have a user id and password for dealerconnect would you?

the signal wire from tcm to pcm(white/orange) shows to be open
 

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Warlockpain, do you have a Email address that I can send some schematic's to you ? Man ! The speedo system in our cars is crazy, what ever happen to a simple cable.
 

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Discussion Starter #13
[email protected] i just disconnected the connector on the bcm that feeds the speedo and drove the car and it still shuts down. at this point i'm thinking maybe bad tcm,but i can't afford to be wrong . and i don't like throwing parts at one until it's fixed! that's not the way i do things.

i would really appreaciate the schematic if you could send it. please and thank you!
 
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