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Cruise control no workie

2001.5 6 spd.

This era doesn't use a vacuum solenoid. Uses rear speed sensor, through ABS module to ECM (per manual).

Quote:

Diesel With Manual Trans. The Vehicle Speed Sensor (VSS) is no longer used for any Dodge Truck. Vehicle speed and distance covered are measured by the Rear Wheel Speed Sensor. The sensor is mounted to the rear axle. A signal is sent from this sensor to the Controller Antilock Brake (CAB) computer. A signal is then sent from the CAB to the Engine Control Module (ECM) to determine vehicle speed and distance covered. The ECM will then determine strategies for speed control system operation

Prior, no cruise light when turning on. Replaced clock spring. Now cruise lights comes on, but set button does nothing. Switch is discontinued, but bought one off ebay. Replaced brake switch in attempt to be thorough. No different. Says it worked when he first tried it, but nothing since.

Says he sees signal from the speed sensor, through the ABS module. OBD isn't sophisticated enough to see signal into/ out of ECM.

Manual offers little and no troubleshooting.

My mechanic is stumped.

Any ideas?

https://cimg0.ibsrv.net/gimg/www.die...f84b1c4ea5.jpg
https://cimg2.ibsrv.net/gimg/www.die...0694c75693.jpg

Quote:

Originally Posted by Rattletrap1 (Post 3356340)

2001.5 6 spd.

This era doesn't use a vacuum solenoid. Uses rear speed sensor, through ABS module to ECM (per manual).

Prior, no cruise light when turning on. Replaced clock spring. Now cruise lights comes on, but set button does nothing. Switch is discontinued, but bought one off ebay. Replaced brake switch in attempt to be thorough. No different. Says it worked when he first tried it, but nothing since.

Says he sees signal from the speed sensor, through the ABS module. OBD isn't sophisticated enough to see signal into/ out of ECM.

Manual offers little and no troubleshooting.

My mechanic is stumped.

Any ideas?

You are right, not much in the manual, but a look at the wiring diagram shows not much can be wrong other than what you have looked at, or perhaps a broken wire...... or corrosion at the PCM connector perhaps?

I don't know if you have the wiring, so let me post it........ I don't know why, but it put the images above.......

Thanks. Printed it out. Not sure what mechanic has. I know he checked a bunch of connections.

Truck is back at home now (with no cruise).

Will call my buddy who's a Western Regional service mgr and see if he can recommend some dealer familiar with these. The mechanic said the local dealer was just as amazed it didn't have a servo. Previously he sent me to Watsonville when I had the injector pump go out and they updated to the in-tank fuel pump. Probably have to wait till the end of hunting season so I can take the camper off and find some place to stash it. Dealers don't want to mess with that on.