b'an AutomotiveTechInfo.com publicationDrain, Drain,Go Away; Dont ComeBack Another Day!The Art and Science of Locating Parasitic Current Draw in Networked Land Rovers (and Other Vehicles) Behold the world of Land Rover diagnostics. Its challenging enough toCommon Current Testing Methods dealwiththeusualcommunicationerrors,multiplemodulefailures,Method 1: DVOM or amp meter as the Shunt Method, Measuring for programming and security issues, and the crazy mechanical failures we seeCurrent Onlyin these vehicles.In amp meter shunt testing for current consumption, you are making the Currentdrains,however,especiallythedreadedintermittentones,canDVOM or meter a part of the circuit in series at the battery to perform the drive even a well-practiced technician crazy for hours or days (particularlytest. This method has several limitations in modern cars, however, when testing for current drains. Not the least of these is the DVOM or meters on newer Land Rover platforms).limited current carrying capabilities (usually 10 amps max) when trying to Granted, some current drains are indeed constant, visible immediately totest modern cars like Land Rovers.our test equipment and traceable quickly and easily in the bay. However,Those of us who have learned this limitation by buying stock (or we may the reality is that in real-world diagnostic practice, 8 times out of 10 we areDV\x03ZHOO\x03KDYH\x0c\x03LQ\x03WKH\x03FRPSDQ\\\x03WKDW\x03VXSSOLHV\x03WKRVH\x03ZHLUG\x0f\x03R\x10VL]H\x0f\x03DQG\x03VXSHU\x10usually chasing an intermittent parasitic ghost.expensive specialty fuses for meters, know full well what I mean. Once the current drain did appear on the DVOM or amp meter, the old tried and true In modulized vehicles, things wake up, glitches happen, or loads cycle onpractice was to disconnect each fuse and observe the meter until the drain DQG\x03R\x03LQ\x03IUDFWLRQV\x03RI\x03D\x03VHFRQG\x0f\x03VHFRQGV\x0f\x03RU\x03PLQXWHV\x0f\x03DQG\x03W\\SLFDOO\\\x03LQ\x03WKH\x03 GLVDSSHDUHG\x0f\x03WKHQ\x03\\RX\x03KDG\x03\\RXU\x03RHQGLQJ\x03FLUFXLW\x11\x03middle of the night when were not watching. Were just simply not likely toBut lets put this older methodology into play in a modern-day networked catch this type of fault while checking only for voltage drop, whilst spazzingLand Rover, such as our example car, a 2016 Range Rover Sport. When we DURXQG\x03WKH\x03FDU\x0f\x03KXQJ\x03DQG\x03SXQJ\x03DV\x03ZH\x03*XPE\\\x03RXU\x03QHFNV\x03XS\x03XQGHU\x03WKH\x03 use this test method in a car like this, a couple of problems arise quickly. dash or climb into the trunk upside-down to try to measure the voltage across fuses in a fuse box we cant even see.First, todays cars will easily overrun the meters 10 amp maximum, even whensimplyopeningthedoorsandwakingupthevehicle.Unlesswe Are we identifying with the frustrations now? To be clear on the voltageprepare the car extensively beforehand, most Land Rovers will wake up dropping of fuses test: If the current drain is not present right now, theand turn on lamps, wake up modules, adjust memory seats, and cycle the millivolts wont be there either and the entire test is a big waste of time. This(OHFWURQLF\x037KURWWOH\x030RWRU\x11\x03/DQG\x035RYHU\x03%XOOHWLQ\x03\x17\x14\x17\x11\x13\x13\x03VSHFLFDOO\\\x03VWDWHV\x03means we need a strategy and a general methodology for our approach. this is the reason NOT to shunt test these cars with your DVOM. 25 8'