b'Thecurrent(measuredinamperes)istheactualelectronmovement6\\VWHP\x03\'HVFULSWLRQ\x03DQG\x032SHUDWLRQ\x03LQIR\x03EHFDXVH\x03WKHUH\x03DUH\x03WKUHH\x03PRGXOHV\x03performingthework,basedonavailablepotentialthroughtheload.and a motor involved in the windows function. Next, wed likely check So, when we want to obtain as much useful information as possible inthe powers and grounds of the modules. After this, we would use a scope anydiagnosticscenario,weshouldconsiderusingcurrentandvoltageor meter to look for any missing signal or command voltages between the measurementsatthesametime.Sometimes,wecanevenusecurrentdoor module, the BCM, and the window motor, after spending 20 minutes measurementalone(andsomestrategy)toavoidaseriousamountpulling schematics and studying them. Then hopefully, by that time we of voltage diagnostics to begin with. Please let me explain, via a recentwould have either stumbled or tested our way into the problem.diagnostic scenario. 1RZ\x0f\x03 WKLQN\x03 DERXW\x03 ZKHUH\x03 ZH\x03 DUH\x03 WLPHZLVH\x0f\x03 MXVW\x03 FRPSOHWLQJ\x03 WKH\x03 UVW\x03 IHZ\x03Diagnostic Scenario: 2017 Jaguar XJR Power Windowsteps mentioned above. The reality is, by the time the tech does all this, Intermittently Binds Up on Customer weve already got at least a half hour to an hour into the job. But if door In this scenario, the owner of a 2017 Jaguar XJR comes in with a strangepanels and other things now needed to be removed for testing the required complaint. She says the drivers power window will intermittently bindvoltages, grounds, and signals, Id venture a guess wed be in for a bit more orfetchupwhengoingupordown.Whenthishappens,eitherthethan an hour. Who knows. Weve all been there. window starts moving again, or it wont work again until the key is cycledThe real challenge with this one is that there are four modules in play here. DQG\x03LW\x03VLWV\x03IRU\x03D\x03ZKLOH\x11\x03%XW\x03VKH\x03VWDWHV\x03LW\x03ZRUNV\x03QH\x03PRVW\x03RI\x03WKH\x03WLPH\x11\x032.\x0f\x03 TheDriversMasterWindowSwitchsendsaLINmessagetotheDoor seems intermittent. What would a conventional approach to diagnosis0RGXOH\x11\x037KH\x03GRRU\x03PRGXOH\x03WKHQ\x03FRQJXUHV\x03D\x03&$1\x03PHVVDJH\x03WR\x03VHQG\x03WR\x03WKH\x03look like then?BCM/GWM for window status and/or control by other systems. At the /HWV\x03VD\\\x03WKDW\x03WKH\x03ZLQGRZ\x0f\x03E\\\x03PLUDFXORXV\x03FKDQFH\x0f\x03\'2(6\x03ELQG\x03XS\x03DV\x03LW\x03LV\x03 same time, the LIN command is sent from the switch assembly to the Door commanded down by the technician while in the bay. The tech hears the0RGXOH\x0f\x03ZKHUH\x03WKH\x03PRGXOH\x03WKHQ\x03VHQGV\x03WKH\x03FRQWUROOHG\x03LS\x10RS\x03YROWDJH\x03RXW\x03WR\x03motor lug down, then recover, and then the window continues on its merrythe Window Motor and Sensor Module to run it up or down.way. Upon trying the up-down routine several more times, there is zeroGreat. Thats a lot of preliminary power and ground checking and looking binding. It only happened once, but the technician did get to see the problemfor signals based on our service information. What if we outsmarted the KDSSHQLQJ\x03LQ\x03UHDO\x10WLPH\x11\x03:KDW\x03ZRXOG\x03WUDGLWLRQDOO\\\x03EH\x03WKH\x03WHFKQLFLDQV\x03UVW\x03 process by a few steps, utilizing current measurement only for this problem? VWHSV\x03WR\x03JXUH\x03WKLV\x03RXW" Could this help cut out several unnecessary steps? Methinks it could. First,wemightcheckforDTCswithascanner,andmaybeperformaHereshowwefoundthiswindowissuequicklyandtookapartand TSB search on the symptom. Lets assume nothing is found here. No DTCresearched nothing in the process. codes are present and there are no applicable TSBs. Then, we may look up The door modules Amp clamp is attachedinternal here for testing logic resets power upon sensing Passenger WindowDriver Windowwindow Module Power Module Power stop limit or current overload.CAN Comms BusStop limit and current overload hall sensorsLIN Comms Bus)LJXUH\x03\x15\x1d\x037KH\x03:LQGRZ\x030RWRUV\x03DQG\x03+DOO\x03(HFW\x03/LPLW\x03DQG\x03&XUUHQW\x03Figure 1: The power window schematic for the Jaguar. NoteOverload Sensors wired to the door modules. The LIN line is used the inter-module comms lines, both CAN and LIN. In thisfor the window commands, the CAN lines likely send data to other vehicle, the window motors are powered and controlled viacritical modules regarding window status. (Zoomed-in capture the door module. (Zoomed-in capture courtesy of MotoLogic) courtesy of MotoLogic)8'