Knock sensor wire harness chewed!!

N

Nativefx

Member
Location
Bend, Oregon
Posted over on the Org. but thought I would post here in case anyone has any additional input:

Okay so the P0328 knock sensor problem I've been researching just got more complicated. I took my FX to a local mechanic and had him confirm the code (originally I pulled at AutoZone) and also had him verify whether it was a problem with the sensor, harness, ECM as indicated in the FSM. He pulled the codes and reset as there were some consistent with a dead battery, which was true.

The codes which came right back were:
P0328 - Knock Sensor
C1103 - Rt wheel speed sensor
C1203 - ABS malfunction

The main problem is P0328. The mechanic took a look and was trying to determine where the problem was. After figuring the sensors were either not getting or returning a signal, he used a mirror and flashlight to look under the intake manifold from the back. He said he found a rodent nest and after removing as much as he could, he saw that the harness had been chewed through completely on one side and partially on the other!!! He said it looks like its chewed right at the connector and so he doesn't believe it can be fixed so he got a quote for a new knock sensor sub-harness for $518, along with gaskets for the upper ($66)and lower intake manifold ($64 x 2 = $128) which he would chance once he removed and replaced the sub-harness. I don't believe this includes new sensors, if they end up needing to be replaced. So the quote he gave me is roughly $1,000 parts/labor.

Questions for this problem is, how difficult is removing/re-installing the intake manifold & gaskets? If it is pretty straight forward, once I get to the knock sensor sub-harness is it a plug & play replacement or is it much more involved? I don't want to pull everything apart and then determine it's more difficult replacing the harness, which i still haven't found an indication of a price on infinitipartsusa. I've only found the full engine harness which is almost $1,000 itself. Or is this something that would be better left to the shop for a grand?

The C1103 & C1203 I need to follow up with the body shop and dealer about as this Rt wheel sensor was replaced about 6,000 miles/less than 1 year ago due to small accident to rt front of the FX (which is why you NEVER let your gf near your keys!). I would guess these two codes would be related. My only concern is, does the sub-assembly harness to the knock sensors have any connection to the rest of the harness/wiring which would go to the wheel speed sensor?

Any comments/recommendations are welcome. thanks
03 Black/Brick FX45
 
Last edited:
the color of the font you copy and pasted isn't readable, at least on the dark theme of this forum, so I copied and pasted it here for you:


Okay so the P0328 knock sensor problem I've been researching just got more complicated. I took my FX to a local mechanic and had him confirm the code (originally I pulled at AutoZone) and also had him verify whether it was a problem with the sensor, harness, ECM as indicated in the FSM. He pulled the codes and reset as there were some consistent with a dead battery, which was true.

The codes which came right back were:
P0328 - Knock Sensor
C1103 - Rt wheel speed sensor
C1203 - ABS malfunction

The main problem is P0328. The mechanic took a look and was trying to determine where the problem was. After figuring the sensors were either not getting or returning a signal, he used a mirror and flashlight to look under the intake manifold from the back. He said he found a rodent nest and after removing as much as he could, he saw that the harness had been chewed through completely on one side and partially on the other!!! He said it looks like its chewed right at the connector and so he doesn't believe it can be fixed so he got a quote for a new knock sensor sub-harness for $518, along with gaskets for the upper ($66)and lower intake manifold ($64 x 2 = $128) which he would chance once he removed and replaced the sub-harness. I don't believe this includes new sensors, if they end up needing to be replaced. So the quote he gave me is roughly $1,000 parts/labor.

Questions for this problem is, how difficult is removing/re-installing the intake manifold & gaskets? If it is pretty straight forward, once I get to the knock sensor sub-harness is it a plug & play replacement or is it much more involved? I don't want to pull everything apart and then determine it's more difficult replacing the harness, which i still haven't found an indication of a price on infinitipartsusa. I've only found the full engine harness which is almost $1,000 itself. Or is this something that would be better left to the shop for a grand?

The C1103 & C1203 I need to follow up with the body shop and dealer about as this Rt wheel sensor was replaced about 6,000 miles/less than 1 year ago due to small accident to rt front of the FX (which is why you NEVER let your gf near your keys!). I would guess these two codes would be related. My only concern is, does the sub-assembly harness to the knock sensors have any connection to the rest of the harness/wiring which would go to the wheel speed sensor?

Any comments/recommendations are welcome. thanks

---------- Post added at 08:52 PM ---------- Previous post was at 08:46 PM ----------

personally I doubt there is any reason to replace the whole harness. the wires will be chewed but I doubt the plastic plug ends are damaged enough to not be usable. the harness could most likely be repaired but this isn't a place to just twist and tape wires or use crimp connectors, everything should be soldered and then heat shrink sealed or water tight sealed. the plug ends can be disassembled and re terminated too. it would have to be seriously bad to warrant replacing I think
 
Thanks turbocad6, I was trying to figure out why I couldn't see the info i pasted.

As for your comment, I was thinking the same thing but the mechanic said he was worried as it looked like they chewed right to the connector plugs and he was worried about whether or not they could get all the right wires to the correct pins if they couldn't tell which they came from. I'm also assuming it's due to the time element about soldering the wire and sealing properly, because they obviously wouldn't want to have to pull everything apart if a solder didn't hold after some time. From what he could see, one is completely chewed through and the other is just about as well.

Any idea on the difficulty of pulling/replacing the intake manifold and gaskets?

Thanks for your help.
 
The intake manifold is pretty easy to remove and install, the screws need to be put back with a torque wrench and make sure you remember where the small hoses go back to.


Sent from my iPhone
 
matrixx860 said:
The intake manifold is pretty easy to remove and install, the screws need to be put back with a torque wrench and make sure you remember where the small hoses go back to.


Sent from my iPhone
Click to expand...


I'm curious to see how bad the damage to the wiring harness is and whether it can be repaired or needs to actually be replaced. If I can remove and replace the intake manifold I can at least take a look to determine, and if the harness sub-assembly is plug/play I may be able to do this myself (if I can find the part on infinitipartsusa). I was planning on trying to change the spark plugs soon, so I figure I could do all of this now but I don't want to start pulling things apart only to find it might be something more difficult than I can handle and end up having to tow it to the mechanic. It runs fine right now, just as smooth as ever but of course the knock sensors not operating is a big deal so I have to get it fixed.
 
Nativefx said:
Thanks turbocad6, I was trying to figure out why I couldn't see the info i pasted.

As for your comment, I was thinking the same thing but the mechanic said he was worried as it looked like they chewed right to the connector plugs and he was worried about whether or not they could get all the right wires to the correct pins if they couldn't tell which they came from. I'm also assuming it's due to the time element about soldering the wire and sealing properly, because they obviously wouldn't want to have to pull everything apart if a solder didn't hold after some time. From what he could see, one is completely chewed through and the other is just about as well.

Any idea on the difficulty of pulling/replacing the intake manifold and gaskets?

Thanks for your help.
Click to expand...

figuring out the wiring is easy, I wouldn't even trust a mechanic to do this who claimed they were worried about whether or not they could get all the right wires to the correct pins if they couldn't tell which they came from. any pro wouldn't have a problem figuring out the wiring and fixing this correctly, and without a solder ever failing. many mechanics are hacks... the best guy to do something like this is going to be an electrical specialist, find a guy who specializes in diagnostics and wiring and the whole job labor and all should cost you less than just the cost of the new harness. shouldn't be that difficult of a repair
 
superman1 said:
Any updates on this??? Wanna know what you ended up doing
Click to expand...

I'm just getting around to having this looked at this week. My buddy who's helping me has been working on our Audi which had much more important problems that needed to be fixed, so he's been working on that for me. I just dropped the FX off with him and he'll probably pull the intake manifold off this week so we can take a look and plan on how to move forward this weekend. I'll let you know how things go......
 
MG]chewedharnesstoknocksensors_zps1b7d5975.jpg[/IMG]
chewedwire_zpsad034cc4.jpg
[/URL][/IMG]

Well here's the damage that was done to the wires connecting to the knock sensors. You can still see some of the remnants of the rodent nest that was under the intake manifold. My buddy is going to soldier the wires back together so we can check to see if the sensors are still good or if either need to be replaced.

Once we determine that, I still need to look for the problem for the ABS code and wheel speed sensor.

I don't care for cats, but I might have to consider putting one in the garage as I normally park my FX during the winter months.
 

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jmanhas said:
damnthat really sucks. I have to replace my knock sensors as well too. how much is that gonna cost?
Click to expand...

My buddy ended up being able to solder the wire back together, but because they are also a shielded type wire it was more work than he thought it was going to be. Once the wire was fixed, I had no more issues with the knock sensor code and the ABS and speed sensor codes were just do to the connecting plug not being fully engaged.
 
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