BY Neil Currie I am not really sure how to explain the vehicle in this month’s article except for saying that visually, it would be enough to make any technician run for the hills! The vehicle in question was a 2008 Land Rover Defender that was dropped off as a non-start. I saw it booked in the diary and upon being handed the job sheet I thought nothing more, that is until I actually stepped outside to see it. To get an idea of what I mean, please refer to Fig.1. See? It wasn’t quite what I was expecting. Never one to shy away from a challenge, I got a push into the workshop and set to work. The vehicle had a note inside which explained that many months ago the engine had failed. Another was then fitted, but afterwards would fail to start. Several people had attempted to get it to run to no avail with one of them cutting the entire harness apart to expose all the wiring. Please refer to Fig.2 This seemed to have been done to ‘check’ if the wiring was ok, but then it was left for months with panels missing and several parts of the engine rebuild unfinished. At some point, my name was mentioned to the owner and the vehicle was trailered down for me to fix it. I don’t know whether I should be flattered or horrified! Regardless of the appearance of the vehicle, at the end of the day it is still something that can be fixed. It just comes down to how much will it cost. Stop, look, listen Confirming the customer’s complaint, I jumped in and gave the engine a try. It would crank over but fail to fire as expected. As I have mentioned before, I always want to look and listen to make sure the replacement engine has some form of compression and the relevant warning lights etc. are displayed to give some form of direction. It was noted that when the ignition was turned on the temperature gauge would go to its maximum reading into 28 AFTERMARKET MAY 2024 TECHNICAL www.aftermarketonline.net RUN FOR THE HILLS! Neil is off the reservation and ready to rock this month with a nonstarting Land Rover Defender, and process is his only ally the red. This could mean several things, the first being that the temperature sensor has not been connected, or is faulty. Alternatively, the engine ECU could has a communication problem. On vehicles that use the popular Ford Transit engine like this one, if the engine ECU is not communicating or malfunctions, the engine temp gauge will default to the max. This is another reason to spend a few minutes in the driver’s seat evaluating things before diving in head first. Scan I then decided to connect a scan tool and see if I could talk to the engine ECU and if so, look at fault codes and live data. Upon connecting I could talk to the module and pulled pages and pages of fault codes relating to all sorts. The ones that interested me the most were relating to the ecu power relay and sensor ref voltage A. Please refer to Fig.3. The relay fault could be an indication of an issue and if the 5v reference circuit was indeed low this would prevent the necessary sensors working correctly for the engine to start so I now had direction and could form a test plan. The plan was to look at live data for sensors which would use a 5v supply and then based on the readings confirm physically that there was 5v present at the sensors if required. Test to prove the theory Looking at live data I could see we had a problem. The MAP sensor, which should read 1 bar with the ignition on, was reading way off and a few other sensors were not matching what I would expect either. It looked like there was indeed a 5v supply issue but as always we test to Fig. 2 Fig. 1
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