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Could it be the ECM?

jdkebuggy

Full Member
Joined
May 2, 2007
Messages
40
Location
Mechanicsburg PA
I have read several posts regarding the same issue I am having with my 02, but can't seem to find the solution. Any insight will be greatly appreciated! A few weeks ago the service engine soon light came on, went to get it checked out and the codes showed a  knock sensor problem. My mechanic replaced the knock sensors and harness according to the service bulletin. The next day the service engine light was back on and codes P0332 and P0327 are back and the engine is running in safe mode. Today while on cruise control, the engine kicked in while I was going up a hill and the service engine light started to blink.  My mechanic thinks its the ECM, but I want to make sure we've covered all bases before I take it to the dealer and dump that kind of money into it.  Any ideas?  Thanks! :E: :E: :E: :E:
 
How well do you know your mechanic?

If DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the KS harness jumper, located at the left rear side of the intake manifold.

Here are some check that can be done if you have a meter.

Disconnect the KS jumper harness connector located on the left side of the intake manifold.
Set the DMM to the 400K-ohm scale.
Measure the resistance of the affected KS using the DMM connected to battery ground.
Is the resistance of the KS within 93K-107K ohms.

If that is good then...

Connect the DMM between the KS signal circuit on the sensor side and a good ground.
Set the DMM to the 400 mV AC hertz scale.

Important:  Do not tap on plastic engine components.

Tap on the engine block near the affected KS while observing the signal indicated on the DMM.
Is any signal indicated on the DMM while tapping on the engine block near the KS?

You can also try to reseat the connector on the PCM and clean the ground locations on the frame.
 
did he have the battery disconnected? it has to be to reset the ecm/pcm or it will not relearn the new knock sensors and cause havoc.

Id reset the codes and disconnect the batt for 1/2 hour and check the connections in the above post. then start chasing bigger issues if that don't work.
 
Thanks, Guys!  I know my Mechanic personally, he is good to me, but this one has him stumped.  I have read your post before and I know your very knowledgeable!!! I don't see that the ECM is a big problem with AV's.  I work on this and let you know.  Thanks, again! 
 
my guess would be a wiring harness problem...possibly an intermittent short
 
Looks like a problem with the no. 2 knock sensor/or harness. Cleaned everything else up. Tomorrow we are going to order another sensor and harness to double check for a defect. We bypassed the no. 2 when the computer showed it wasn't working properly. Truck ran great with the bypass. Will update once we get it figured out.
 
put the good sensor in the bad hole and the newest one in the 1 spot..... if it still goes off the deep end it might be picking up a knock????
 
How well do you know your mechanic?

If DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the KS harness jumper, located at the left rear side of the intake manifold.

Here are some check that can be done if you have a meter.

Disconnect the KS jumper harness connector located on the left side of the intake manifold.
Set the DMM to the 400K-ohm scale.
Measure the resistance of the affected KS using the DMM connected to battery ground.
Is the resistance of the KS within 93K-107K ohms.

If that is good then...

Connect the DMM between the KS signal circuit on the sensor side and a good ground.
Set the DMM to the 400 mV AC hertz scale.

Important: Do not tap on plastic engine components.

Tap on the engine block near the affected KS while observing the signal indicated on the DMM.
Is any signal indicated on the DMM while tapping on the engine block near the KS?

You can also try to reseat the connector on the PCM and clean the ground locations on the frame.
I'm troubleshooting on my '05 Z71, what do you mean by "between the KS signal circuit on the sensor side"?
I recently replaced both sensors and the harness and now instead of one KS code I have two. Used the Blue Driver KS video and followed all steps. Tested KS after install (wish I'd have done them before) through the harness and I believe I got a reading of about 94k-96k ohms.
The CEL stays off if I stay under 50 mph. I was going to start a thread on this and may yet depending on what I can find already posted, especially since some are pretty old.
 
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