Engine/Transmission (1994 - 1998) crank speed sensor ?

[FHerault]

Hello,



Yesterday, when I started the truck, the tachometer, the speedometer, and the wait to start light didn’t work. After a few miles, I decided to cancel my trip and go back home...

I’ve found several posts on the subject and tried to check the engine speed sensor over the crank.

I just want to be sure, because my english is what it is...

So,



1 - When I disconnect the sensor, and put the key on, the wait to start light comes on.

2 - Always with the sensor disconnected, I check the continuity between the terminal (black/light blue wire) and a good ground on the truck and it’s ok, so I presume I’ve a good ground from the pcm.

3 - When I check the voltage between the ground and the violet/white wire terminal, I have 5. 15 volts that seems to be ok.

4 – When I check the voltage at the grey/black wire terminal (signal) I have 3. 18 volts... ?

5 – On the sensor, when I check continuity between the red (violet/white in the harness) and the black (ground, black/light blue in the harness) wire terminals, I have continuity.



Do you think I’m good for a new engine speed sensor ?

At the nearest auto-parts, they sell it 300 CAD$, I think it’s a bit expansive for a magnet...

Thanks in advance for any advice...

 

[Missouri Mule]

The engine speed sensor(ESS) sends signal to PCM and activates the Automatic shut down realy (which sends voltage readings to the EVR located in the PCM) any way the PCM uses the data from ESS for several things.

I've heard of the tach,volts,a/c, overdrive, and speeddometer not working but not the "wait to start light" because of a bad ESS. I think you need to look at the air intake tempature sensor for that.

Is the 3. 18 volts engine off or engine running? If ignition is turned to run but engine is not running I think your ESS is messed up. If your engine is running then 3. 18 volts mite be good and your PCM is messed up. Your instruments mite be messed up.



Check Geno's Garage Dodge Cummins Diesel Truck Accessories - Geno's Garage

 

[FHerault]

Thanks for the reply.



The 3. 18 volts is engine not running and key on, sensor disconnected.



When the sensor is disconnected, the wait to start light comes on, it's why I think the ESS is bad. Do you think I'm wrong ?

I forgot to say that the shifting was bad, it seems that the truck take off in 2nd gear...



I've ordered the ESS from cummins because I've got to go on... they couldn't find one anywhere in Canada so it will fly from the US in 24 hours... less than half the price from a dodge dealer... wait and see

 

[FHerault]

Just my feed back...

I've changed the ESS. I bought it at a good price in a Cummins dealer (they've received it by plane in less than 24 hours), all seems to work now (wait to start light, charge circuit, tachometer... )

 

[Missouri Mule]

Glad to hear your truck is up and running again!



Apparently the ground or power of the ESS sensor is inline with the intake temp sensor. The PCM supplies power and ground to most sensors.

 

[FHerault]

Thanks Missouri Mule.