I have a disco II 2000. The torque converter and flex plate was replaced Apr 2015. About 3 months ago the check engine light came on. My icarsoft reader shows an open for the lockup solenoid. My guys did a solenoid and continuity check. Everything is ok. On the ECU connector, pin 32 is the lockup. Pin 6 and 28 are earth ground. Pin 53 is the solenoid valves power supply. How do I check to see if MV3 solenoid is getting power at lockup speed? Could this be a problem the transmission ECU.

 

Need to know if the TC is locking up, is it? In other words do you know whether it's a LU problem or just indication giving a code?
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That is a good question. I am not sure how to check for LC lockup. I can put the icarsoft in real time output and monitor the engine rpm at lockup speed (55 mph) for decrease in rpm. Or lightly touch the break pedal and look for a increase in engine rpm. Also, if I knew for sure which pins energize the solenoid, I can tap into those pins with a volt meter to see if there is power on that circuit at lockup speed.

 

Found on my D2 it's apparent by just driving. Don't have exact ##s in head but at about 55 mph and trans has just shifted to high gear my tach RPMs about 2200 and once TC locks they drop to below 2000. Happens fast when trans warm and may be easier to see when cold.
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I will check with my reader. It puts out rpm in actual numbers. The only reason I need to correct the fault is because of emission inspection. Otherwise I would not worry with it.

 

Understand per the emissions. Once you determine if working or not the wiring diagrams are available for download. The Electrical Library portion shows connector locations and usually has a good D&O.

You can go here:
land rover service factory manual RAVE download land rover resource, service manual, workshop factory manual, download, rave, vehicles including discovery, series, defender, range rover, freelander, LR3, Handbooks, Catalog, Catalogue, Land Rover Inte
Save the zip file from link that looks like this:
Land Rover Rave Service Manual large file warning 590MB
Takes awhile to download, it was longer than 30 minutes on my DSL connection. PDF "rave-lr" is in there and probably all you need. Save/Move on your drive where your other manuals reside. Open up, go to your vehicle type and you should be able to find the manuals you may desire.
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I have the manual. What I am not clear on is ground for the lockup. It shows pin 53 as power to the solenoids and pin 32 for the lockup. Is pin 32 the ground and does the ECU energize the lockup with the ground.

 

D2 manual not clear, found the last in another manual and suggests it's the gnd circuit. Last little bit sounds as if ops normal there could be some high resistance in coil/circuit setting fault.
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Number9 Thanks. I am going to check the continuity between pin 53 and pin 32. Then I am going to check the voltage with a volt meter between output pin 32 and the solenoid power pin 53. At lockup speed this should show a voltage. Is this correct. Also is the resistor network in the ECU.

 

Yes along with processor as parts of ECU.

Solenoid coil resistance should be checked for 32.5 +/-2 Ohms. If planning to back probe for voltage check and you will have voltage there through coil prior to LU command and suppose you'd see a voltage drop when LU is supposed to occur.
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