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Dodge Repair/knock sensor jumper kit: 2.7L


QUESTION: i have a 2002 dodge intriped  with a bad knock sensor .I have a sensor jumper but have no idea were is is to be installed con you help

ANSWER: Hi John,
There are two possible engine types (2.7 or 3.2/3.5L), and you didn't say which you have. Also, I am not sure what the purpose is of the 'jumper'? I assume that it is to take the place of a bad sensor, so presumably you would go to the faulty sensor, remove its plug and substitute the jumper in its place.
Are you asking where is the sensor located? Tell me the engine (L). And describe what the jumper looks like as regards it's electrical socket(s) and mechanical attachment point if any.

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QUESTION: the engine is 2.7 I ran the codes and it comes up bank one sensor one bad knock sensor motor runs good but cannot go to inspection c.e.l is on. was told to buy knock sensor jumper wire kit from dodge called dodge but no help sell parts but wont help .the jumper is 16 in. long with connectors on both ends it is to bypass sensor but the connectors are different. cannot plug it into harness were the sensor would go and have no idea were the other end should go . I have new sensor but I am not going to pull apart intake and head to replace. I can cut off old sensor plug and splice one end but do not know were  the other end should go .
part number of jumper is 1-04759491ab mopar.

ANSWER: Hi John,
There is no place (unused plug or socket) set aside to plug in a "jumper", as far as I know.  Thanks for the photo of the jumper.
You mentioned that you were advised to buy this 'jumper kit', but you didn't say by whom, nor what was the purpose of the jumper. I doubt that there is a way to get around a faulty knock sensor circuit fault code by means of such a 'jumper' as shown in the photo.
My first thought is that you haven't found the old knock sensor and so removed the wrong plug. The one picture I have of the sensor (with no mention of which engine is shown) shows it to be on the side of the block, positioned between the end of the starter motor and a large water hose that goes into the block. Another possible location would be in the block, below the throttle body.
The sensor plug itself is  either round shaped and gray in color (looks like one end of the jumper piecture you sent me) and has 2 wires (black/light blue and black/violet); or another possibility is that it is black and rectangular in shape with black/violet and dark blue/light green wires. The plug shape/wire colors changed at some point and I don't have the '02 manual, rather only the '99 and '03 manuals so I don't know for sure about your '02 year sensor.
So verify that you actually have the knock sensor located along with its wiring plug.
Another thought is that the jumper is merely for the purpose of attaching the existing gray plug into a later year model NEW knock sensor which has the rectangular plug and which may be the only type of sensor you can now buy to replace a bad sensor. So maybe what you need to do is replace the old sensor with a new sensor and if you can only get one with the rectangular plug then that is what the jumper is for.
While you decide about replacing the sensor (has the new one the same plug socket as the old sensor?), did you happen to check the continuity of your sensor's plug wires back to the PCM? It is possible that the sensor is OK but one of the two wires is "open". I believe one wire is connected to pin 43 and the other to pin 25 at the pcm. Verify those connections as the sensor itself may not be bad. If the wires are good and the sensor is then bad I would question whether the jumper alone will eliminate the check engine light issue. You may have to replace the knock sensor after all. In that respect you may have misunderstood the purpose of the jumper kit as a possible 'fix' by itself.
I will be interested to know what you learn.
Please read the PS below and say 'yes' to a 'nomination' of me.

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QUESTION: hi Roland
On my 2.7 the knock sensor is located under the right side head to replace I will have to remove the intake and head not willing to go that far . I was reading on another forum about the jumper ordered it from berry dodge in Texas I have a new sensor it has a rectangular plug wire colors black/violet blue /green trace I followed the wire back to the pcm
witch has 4 large plugs found the one witch holds sensor wires but cannot tell witch pin is witch all this trouble just to pass inspection.

thank you
ps if there is any other info I would love to know

Hi John,
I assume then that the original knock sensor may have a round gray plug, correct? If so, then the jumper would be of use if you did have to put in the replacement sensor. If the original sensor has the rectangular plug already then you won't need the jumper.
As to the wires, the dark blue/light green on pin 2 of the sensor plug goes to pin 25 of the number 2 38-pin plug at the pcm, while the black/violet on pin 1 of the plug goes to pin 24 of the same plug. If you look carefully at the plug where the wires go into the holes you should see numbers engraved for each hole. So check both for continuity of each wire, and also check that there is no connection/short between the two wires. Best of luck on solving this.

PS Thanks for the rating/nomination. I do see that indeed to replace the sensor you would need to remove the manifold and the cylinder head. I did notice also that the manual says that the performance of the sensor depends upon the torque setting of its retaining bolt. The specified torque is 7 foot-pounds so if indeed the sensor is the issue, rather than the wiring, I wonder if you might be able to reset the torque on its bolt to solve the problem. I just can't visualize the position of it and whether the bolt is accessible to you without removing the head.

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Roland Finston


Free fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question or asleep overnight so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2011 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top expert" from 2010-2015 here at AllExperts, and have answered 20,000+ questions.


Five decades as a 'do-it-yourselfer' on domestic and imported cars

Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Degrees in Physics/bruised knuckles.

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"Top expert" of 2010, 2011, 2012, 2013, 2014, and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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