Speed Sensor

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Feb 10, 2012 | 06:31 PM

BMac329

Thread Starter

Seasoned Member

Joined: Mar 2011

Posts: 346

Likes: 1

From: Pittsburgh, Pa

Year: 1999

Model: Cherokee

Engine: 242CI 4.0L I6

Speed Sensor

Anyone ever have a P0720 engine code on the 42RE trans. Output speed sensor circuit malfunction.

Anyone have any ideas, other than obviously taking out the VSS and checking it.

Feb 10, 2012 | 08:17 PM

Bustedback

CF Veteran

Joined: Feb 2010

Posts: 12,367

Likes: 23

From: Oroville, CA

Year: 1995

Model: Grand Cherokee

Engine: 4.0 with all of the noise and clatter

Sometimes the speed sensor will get ATF in it and foul up. Just replace it if you don't see any damaged wiring going to it.

Feb 10, 2012 | 08:21 PM

xjbeadlocks

Senior Member

Joined: Jan 2012

Posts: 535

Likes: 0

Model: Cherokee

Quote:

Originally Posted by Bustedback

Sometimes the speed sensor will get ATF in it and foul up. Just replace it if you don't see any damaged wiring going to it.

thats funny you say that. just had a 97 (I think it was) come in the shop this week with the same issue

Feb 12, 2012 | 01:32 AM

jnicewan

Senior Member

Joined: Dec 2010

Posts: 698

Likes: 2

From: Norman, OK

Year: 95

Model: Grand Cherokee

Engine: 4.0

Quote:

Originally Posted by BMac329

Anyone ever have a P0720 engine code on the 42RE trans. Output speed sensor circuit malfunction.

Anyone have any ideas, other than obviously taking out the VSS and checking it.

You do know the OSS and VSS are two different sensors right? The OSS is on the trans O/D housing, LH side and faces slightly downward, it unscrews from the housing. The VSS is on the back of the t-case. The PCM will use the VSS for a back up signal when the OSS fails though.