Hello All Any help would be greatly appreciated 2004 749 Riding about a month ago in traffic (still warmish days so temperature went up as normal) fans kicked in, then --- (three dash) on temperature reading. Now fans kick in on ignition with engine light. Have EFI code 3.1 (water sensor is shorting on power supply) and P0115 Engine coolant temperature circuit malfunction high input through diagnostic obd. I've replaced the coolant sensor to no avail. Reading up on this it's a possible ECU earth short, however this should rectify it self when the diagnostic cable is reconnected, which it doesn't, so I'm pretty sure it's not that. My next course is battery off and wire checks. Has anybody got any other ideas? I hate electrical issues Many thanks in advance
Go through the cheap stuff first. Check wiring loom for chaffing or broken wires. There is a connector under the tank that is prone to chaffing. Replace the coil/injector/pump relay in the battery box. If all that fails then you are probably looking at another ECU. You can get away with using second hand. Identify if you have an IAW 59M or IAW5AM. They can be reflashed to suit with immo off or virginised.
