Solenoid pattern question

Craig Technical Support Specialist Chicago, Illinois Posted   Latest  
Question
Driveability
2006 Jeep Grand Cherokee Limited 5.7L (2) 5-spd (545RFE)
P3497 - Cylinder Deactivation System Bank 2
P2101 - Throttle Actuator "A" Control Motor Circuit Range/Performance

Working on this vehicle having MDS problems. I understand that there is a list of high failure items and I want to try to gather as much possible information before opening the patient. With the code P3497, an oil flush and change will be performed, customer added heavy weight oil trying to quiet the motor. I found very little testing information and decided to current ramp the MDS solenoids. First image is a bank one solenoid being commanded on with a scan tool. This looks like what I expected to find considering the style solenoid, both solenoids on bank one looked similar. 

Second image bank two, cylinders 4 and 6 both look like this? Could these solenoids be dragging that much? or just completely mechanically worn out? I found a resistance spec online stating value should be 10.55 ohms, solenoids bank one are calculated at 6.96 ohms, bank 2 4.6 ohms. 

Next issue P2101, if I have a cylinder that cannot reopen its exhaust after being reactivated could the resultant pressure wave in the intake push my throttle plate away from desired position setting this code? I ask because both codes were set with the vehicle moving and hot first the P3497 eight miles later P2101, vehicle has new throttle body and connector.

Vehicle is also getting in cylinder pressure tests on MDS cylinders in an attempt to check valve train condition.

Any ideas of tests to be done, recommendations to run like hell, as well as further guidance are all welcome.

Craig

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Caleb Diagnostician
Mishawaka, Indiana
Caleb Default
   

Can you post the PICO files so we can zoom in on the #1 capture? Cant see the pintle bump at all. #6 solenoid pintle bump looks perfect in capture 2. These solenoids draw about 1 amp which is what we have on the number 6 cylinder. You need to put a pressure transducer in #6 and command the solenoid when running and see if the cylinder waveform responds accordingly. Compare to #1 cylinder if that…

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Helpful
Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

Thanks for the information Caleb, I am not sure I can command the solenoid with the engine running ( autel ). Also no codes for solenoids, all can be heard clicking on and off. In cylinder pressure waveforms look good comparing cylinder 7 suspected good to numbers 4 and 6 patterns when compared with 7 as a reference are absolutely identical. Do you have a current capture from a known good…

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Caleb Diagnostician
Mishawaka, Indiana
Caleb Default
   

I just pierce my own 12 v on the MDS solenoid when the car is running. I dont even use the scanner. And I'm not trying to be a jerk but are you testing the correct banks?? Cylinders 1357 are drivers side and 2468 are pass. side. No I dont have a known good. But the one posted looks fine. Almost any solenoid looks similar to what you posted. Transmission, VVT, EVAP,Injector,etc. Again with…

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Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

I actually have a current probe around all 4 wires at the pcm, I could very well be testing the wrong banks I am trusting the scan tool to be accurate. I agree there should be a pintle bump but it seems very drawn out, I may order one for "testing purposes". I know tonight it got an oil flush and change, tomorrow when I go in I will power the solenoids while checking in cylinder pressure to…

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Niall Owner/Technician
Stirling, United Kingdom
Niall Default
 

Hi not a reply relating to electronics, I had one of these Jeeps in (it had been to the dealer to sort out a misfire). I agreed to have a look at it. Push rod had jumped out of rocker arm and stayed there. Dealer had replaced MDS solenoid. Niall

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Craig Technical Support Specialist
Chicago, Illinois
Craig Update
 

Thanks Caleb your testing method worked on this vehicle, energizing solenoids for cylinders 4 and 6 produce misfires, energizing # 7 nothing happens, energizing # 1 stalls the vehicle every time, obviously I have an issue with my bank one solenoids. Customer will be notified with the update and we will see what repairs are authorized, whether to replace the 2 bad or do all 4 since were already…

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Dennis Owner/Technician
Plymouth, Michigan
Dennis Default
 

Id be leary servicing that engine if somebody did an oil flush​.​Unless your gonna replace everything you asking for problems down the road​.​You touch it you married it.

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Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

Vehicle had engine flush added Friday night ran for 10 minuets sat overnight and was run again Saturday for an additional 15 minuets idling. Oil was changed and filled with proper viscosity oil,solenoids for cylinders were activated using a Snap-On EECT900 power probe set to pulse mode, after a moment the #1 solenoid began to make intermittent clicking sounds letting it pulse for another couple…

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Craig Technical Support Specialist
Chicago, Illinois
Craig Default
 

Customer has had no issues with this vehicle since testing. Issue resolved.

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Craig Technical Support Specialist
Chicago, Illinois
Craig Resolution
 

Customer has not had any issues since picking up the vehicle. Problem resolved.

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