[Chump]

Have you scanned the computer for error codes?

Description and Operation
The vehicle speed sensor is located in the extension housing of the transmission (2WD), or the extension housing of the transfer case (4WD).

PURPOSE

Sensor is used to inform Powertrain Control Module (PCM) of vehicle speed, vehicle acceleration, or deceleration.

OPERATION

Vehicle Speed Sensor (VSS) Typical

Sensor generates 8 voltage pulses per axle shaft revolution (sent directly to PCM).

PCM uses sensor input with input from Throttle Position Sensor (TPS) to determine closed throttle deceleration or closed throttle idle (vehicle stopped).

During idle, (no signals being received from sensor), PCM actuates Idle Air Control (IAC) motor to maintain desired engine idle speed.

During closed throttle deceleration, (slower signals received from sensor), PCM actuates IAC motor to maintain desired Manifold Absolute Pressure (MAP) sensor value.

The vehicle speed sensor input signal is also used as a mileage reference for the Service Reminder Indicator (SRI) lamp, and also to maintain speed control operation.

 

[MulesHemi]

nice post thanks

 

[MulesHemi]

well i took my truck in to my college to have the auto guys look at it and all they really did was run it for codes and found 4, one for the alt. one for the IAC, one he couldn't remember and now one that i cant remember, anyway it hasnt died since.
there are a few other problems all ask you about though since this is going.
my oil pressure is funky, sometimes it drops to zero at start up, i hit the gas immediately and it jumps back up. ideas?
by the way heres the prices i picked up on the sensors from napa, just pricing them out
MAP $98.99
Speed Sensor $121.39
IAC $56.69
Coolant temp (pcm,not gauge) $13.29

 

[Chump]

Check out www.rockauto.com for cheaper parts prices.
Map...$59
speed sensor...$102
IAC...$33 to $56

 

[firefighter51]

ive kinda had similar issues with my truck... i got the 5.2.. i runs pretty rich and i thing the only sensor i have replaced ins the thrmostat. like if i dont let it warm up, it idles very low when i come to a stop, almost like is gonna stall. maybe one of you guys can help.

 

[MulesHemi]

just wish i knew why it runs soo rich