Wiring Harness Varied Resistance
Thread Starter
Junior Member
Joined: Apr 2017
Posts: 27
Likes: 0
2007 GL 450
Wiring Harness Varied Resistance
Hi everyone, I've been trying to wrestle a few issues to the ground recently and I'm coming back to a common theme.
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
Senior Member
Joined: Aug 2014
Posts: 336
Likes: 46
gl450 530i
Hi everyone, I've been trying to wrestle a few issues to the ground recently and I'm coming back to a common theme.
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
what year is your gl might neeed a new timing chain
Super Member
Joined: Aug 2008
Posts: 528
Likes: 20
From: Chicago IL
X166 gls450 2017
Hi everyone, I've been trying to wrestle a few issues to the ground recently and I'm coming back to a common theme.
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
I'm concerned my engine wiring harness is going bad. I'm new to the GL450 so I've not had much experience with this.
I have a code P0410 that keeps creeping back. Recently my car stalled three times while at moderate speed (40-55 mph). During those stalls, the car threw several codes at me including: P0393, P0340, P0102, P0607, P0101, P0343, P0348, P0368
These codes suggest that all of the camshaft sensors are having trouble and at the same time the MAF sensor is bad if I'm not mistaken.
All of these systems (MAF, Camshaft Sensors, and the Secondary Air Pump) feed through that same wiring harness.
To test my theory I pulled the power cable on the secondary air pump and tested the ground side. There was resistance between the pump ground connector and the ground on the car. I then moved the wiring harness during this measurement to witness the resistance change dramatically.
Has anyone else had these issues or something similar? I've had the car to the dealer who failed to diagnose the stall issue and incorrectly diagnosed the secondary air problem. Since they didn't say that the ECU is bad I'm hoping that it isn't the whole computer.
I would appreciate any thoughts you might have!
Thread Starter
Junior Member
Joined: Apr 2017
Posts: 27
Likes: 0
2007 GL 450
Thread Starter
Junior Member
Joined: Apr 2017
Posts: 27
Likes: 0
2007 GL 450
Former Vendor of MBWorld
Joined: Mar 2017
Posts: 335
Likes: 12
na
Sorry to hear you're having issues with your ride. If it turns out you do need work done on your ecu we offer a repair service that is well below dealer pricing. Let's hope it doesn't come to that though!
Thread Starter
Junior Member
Joined: Apr 2017
Posts: 27
Likes: 0
2007 GL 450
An update on my issue:
I removed the front SAM (located under passenger seat) and disassembled the module that might have been the culprit. No obvious damage to the unit and it does appear to be in good condition. No loose leads, so scorching, no water infiltration. (Photos attached)
If anyone has had issues with the SAM before, was the issue obvious? Or was the damage simply in the programming of the module and therefore can't be seen without SDS?
Is there a way to test this module without SDS (probably not)? I reinstalled the module after giving it a good canned air cleaning just in case in introduced any unwanted contaminants.
I think I'll pull the wiring harness just to see if there is anything obvious.
If there are any other thoughts I'm very open to listening. Thanks again!
Other recent work I did that may or may not be relevant:
1. Replaced Airmatic Compressor, filter, and input hose
2. Replaced Crankshaft Position Sensor (possible solution to stall issue)
I removed the front SAM (located under passenger seat) and disassembled the module that might have been the culprit. No obvious damage to the unit and it does appear to be in good condition. No loose leads, so scorching, no water infiltration. (Photos attached)
If anyone has had issues with the SAM before, was the issue obvious? Or was the damage simply in the programming of the module and therefore can't be seen without SDS?
Is there a way to test this module without SDS (probably not)? I reinstalled the module after giving it a good canned air cleaning just in case in introduced any unwanted contaminants.
I think I'll pull the wiring harness just to see if there is anything obvious.
If there are any other thoughts I'm very open to listening. Thanks again!
Other recent work I did that may or may not be relevant:
1. Replaced Airmatic Compressor, filter, and input hose
2. Replaced Crankshaft Position Sensor (possible solution to stall issue)
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Super Member
Joined: Aug 2008
Posts: 528
Likes: 20
From: Chicago IL
X166 gls450 2017
An update on my issue:
I removed the front SAM (located under passenger seat) and disassembled the module that might have been the culprit. No obvious damage to the unit and it does appear to be in good condition. No loose leads, so scorching, no water infiltration. (Photos attached)
If anyone has had issues with the SAM before, was the issue obvious? Or was the damage simply in the programming of the module and therefore can't be seen without SDS?
Is there a way to test this module without SDS (probably not)? I reinstalled the module after giving it a good canned air cleaning just in case in introduced any unwanted contaminants.
I think I'll pull the wiring harness just to see if there is anything obvious.
If there are any other thoughts I'm very open to listening. Thanks again!
Other recent work I did that may or may not be relevant:
1. Replaced Airmatic Compressor, filter, and input hose
2. Replaced Crankshaft Position Sensor (possible solution to stall issue)
I removed the front SAM (located under passenger seat) and disassembled the module that might have been the culprit. No obvious damage to the unit and it does appear to be in good condition. No loose leads, so scorching, no water infiltration. (Photos attached)
If anyone has had issues with the SAM before, was the issue obvious? Or was the damage simply in the programming of the module and therefore can't be seen without SDS?
Is there a way to test this module without SDS (probably not)? I reinstalled the module after giving it a good canned air cleaning just in case in introduced any unwanted contaminants.
I think I'll pull the wiring harness just to see if there is anything obvious.
If there are any other thoughts I'm very open to listening. Thanks again!
Other recent work I did that may or may not be relevant:
1. Replaced Airmatic Compressor, filter, and input hose
2. Replaced Crankshaft Position Sensor (possible solution to stall issue)
Last edited by 007_e350; Apr 21, 2017 at 12:32 AM.
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Before you do any digging into the wiring remove cam sensors and look inside if the markings have moved. It certainly sounds like your timing (chain) is bad.
What resistance to ground are you observing? There might be some but it should be in the ohms range. Up to 60-100 is prolly ok.
What resistance to ground are you observing? There might be some but it should be in the ohms range. Up to 60-100 is prolly ok.
Last edited by alx; Apr 21, 2017 at 02:03 PM.
Thread Starter
Junior Member
Joined: Apr 2017
Posts: 27
Likes: 0
2007 GL 450
Thanks 007_350 and ALX for your help with this. I'm still not sure that I've worked out all of the issues at this point.
However I did pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related but a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
However I did pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related but a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
Last edited by OldRockyTop; Apr 23, 2017 at 01:42 PM.
Senior Member
Joined: Aug 2014
Posts: 336
Likes: 46
gl450 530i
Thanks 007_350 and ALX for your help with this. I'm still not sure that I've worked out all of the issues at this point.
However I didn't pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related but a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
However I didn't pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related but a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
minimum 5k...ask me how i know
Super Member
Joined: Aug 2008
Posts: 528
Likes: 20
From: Chicago IL
X166 gls450 2017
Thanks 007_350 and ALX for your help with this. I'm still not sure that I've worked out all of the issues at this point.
However I didn't pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
However I didn't pull the top of the wiring harness apart this morning. I followed the ground wire of the Secondary air pump and voila, bad ground. That system is working perfectly now, and I'm posting a picture of the wiring harness ground location for anyone who might need to check that as part of an electrical issue. (I've marked it's location between the last and second to last ignition coils on the passenger side of the engine. Note the orange marker)
I'm not sure if that ground might have impacted the cam sensors, but I'll wait and see if those issues come back. They probably aren't related a man can hope.
I'm sure the timing chain would be an undertaking that I'm not capable of, so do you know what I should plan to pay for such an operation?
Thanks again!
One of the symptoms of extended timing chain is clattering sound on cold start, plenty of info on here, there's actually a fellow member that wrote up full diy with pics not too long ago, let me know if you can't find that post
Thread Starter
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2007 GL 450
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Posts: 336
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gl450 530i
i replaced mine at 166k it only affected the 07 mainly. it did start to show symptoms around 150k. it really varies by driver and maintenance though
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GL 450
Hello everyone. I have a 2009 GL 450 that keeps displaying a 'Malfunction' indicator with an arrow pointing underneath the vehicle. The back bounces as I ride down the street. It doesn't do this all the time. What could be the issue?
