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2008 Jag XJ8 don't start & scanner can connect with ECU
Hi, I just bought a Jag XJ8 L, but it don't start & tje scanner can connect with ECU. You can turn on the switch and it power the whole dashboard, but it won't crank, and the shifter is stock in parking, also the air suspension are flat at the floor level.
when we tried different scanners, we couldn't connect with the ECU, should we have to replace the ECU or have anyone experienced a similar problem? Thank you in advance.
Hi, I just bought a Jag XJ8 L, but it don't start & tje scanner can connect with ECU. You can turn on the switch and it power the whole dashboard, but it won't crank, and the shifter is stock in parking, also the air suspension are flat at the floor level.
when we tried different scanners, we couldn't connect with the ECU, should we have to replace the ECU or have anyone experienced a similar problem? Thank you in advance.
I feel like I am always making the same suggestion, but here goes :-)
Disconnect battery.
Remove the windshield wipers and pull the plastic fasteners out of the large plastic panel beneath the wipers. On the passenger side, below the lower left corner (when facing the engine) of the windshield is the cabin filter. Remove it.
Within this housing you will find a 10mm bolt in the front, and 4 10mm nuts securing cabin air intake housing, remove them all.
Now remove the cabin air intake and the lower housing.
You will find the back of the main ECU and its harness, which is secured with a 5 point torx style bolt. Remove this and inspect the inside of the connectors on both sides.
If all looks good then proceed with cleaning out the rubber drain just below, on top of the inner fender.
Reinstall everything in reverse order (with a new cabin filter).
This should be the first thing you check and verify is in good working order. When that drain gets clogged it will cause water to drain onto the ECU and connectors, leading to numerous difficult-to-diagnose problems. Once confirmed as good and not corroded, you can proceed to troubleshooting other components. The other thing I recommend to do right away is to use a logic probe to test all of the fuses in the car. The top of each fuse has direct access to both blades. Just touch both sides to confirm that the fuse has continuity (and the same polarity on both sides). One last thing to check before proceeding to troubleshooting, is to make sure the battery potential is 12.6 volts.
With these cars it is not a simple ECU replacement. The ECU checks for the correct VIN. If the VIN does not match what is stored in the in the ECU, it will not start. This water damage is what leads to many of these cars to become junked since it is a big expensive ordeal to replace the ECU (but it can be done). Let us know what you find. Good luck.
I
With these cars it is not a simple ECU replacement. The ECU checks for the correct VIN. If the VIN does not match what is stored in the in the ECU, it will not start. This water damage is what leads to many of these cars to become junked since it is a big expensive ordeal to replace the ECU (but it can be done). Let us know what you find. Good luck.
-j
even with a junk $40 SDD setup there is a quick and easy ways to get it running with no risk and no flashing
[QUOTE=Jacuar;2478330]I feel like I am always making the same suggestion, but here goes :-)
Disconnect battery.
Remove the windshield wipers and pull the plastic fasteners out of the large plastic panel beneath the wipers. On the passenger side, below the lower left corner (when facing the engine) of the windshield is the cabin filter. Remove it.
Within this housing you will find a 10mm bolt in the front, and 4 10mm nuts securing cabin air intake housing, remove them all.
Now remove the cabin air intake and the lower housing.
You will find the back of the main ECU and its harness, which is secured with a 5 point torx style bolt. Remove this and inspect the inside of the connectors on both sides.
If all looks good then proceed with cleaning out the rubber drain just below, on top of the inner fender.
Reinstall everything in reverse order (with a new cabin filter).
This should be the first thing you check and verify is in good working order. When that drain gets clogged it will cause water to drain onto the ECU and connectors, leading to numerous difficult-to-diagnose problems. Once confirmed as good and not corroded, you can proceed to troubleshooting other components. The other thing I recommend to do right away is to use a logic probe to test all of the fuses in the car. The top of each fuse has direct access to both blades. Just touch both sides to confirm that the fuse has continuity (and the same polarity on both sides). One last thing to check before proceeding to troubleshooting, is to make sure the battery potential is 12.6 volts.
With these cars it is not a simple ECU replacement. The ECU checks for the correct VIN. If the VIN does not match what is stored in the in the ECU, it will not start. This water damage is what leads to many of these cars to become junked since it is a big expensive ordeal to replace the ECU (but it can be done). Let us know what you find. Good luck.
12-21-2021 | 10:51 PM
2008 Jag XJ8 don't start & scanner can connect with ECU
