Land Rover Common ECU Faults
ABS light comes on
Shuttle Valve Fault code
ABS Pump fault code
Inlet/Outlet valve fault code
This is a very common failing part, if your ABS light has come on and you are getting Shuttle Valve fault codes. .
Motor Industry management article by Roger Bagg, Peacock & Purvey Range Rover v8 90-93
This problem was a sulky Range Rover
that got upset if left alone too long. It would start fine every morning if it was used every day, but if it was not used for a day then the next morning it would be really mardy , coughing and sneezing until warmed up. It didn’t like cooperating with the Doctor either when we checked it over we couldn’t find anything wrong with it at all. Still that was with a hot engine, so we fitted more test gear on to it and left it to sulk for a while. Checking it with a cold engine showed a fault with the coolant temperature sensor that was behaving itself fine when it was hot. After renewing this sensor it was still not 100 % so we took it’s brain out (Ecu or electronic control unit that should control the bits on the engine to do the right things) and tested it on our computer. We found that the brain wasn’t controlling the devices on the engine properly. on cold running conditions and ,after fitting a reconditioned brain the car was cured. For more info on ECU testing click on ECU.
Land Rover, all models 1993 - 2004 onwards
High CO & low lamna reading. common causes of rich running faults are the lamna sensor or the ECU (engine control unit) both of these parts are relatively simple to check, to check the sensor strip back the insulation on the signal wire from the lamna sensor, this wire is usually black. Then hold the bare wire between your finger and thumb then touch your other hand on to the battery positive the internal resistance of your body will give 1volt at your finger tips which is what the sensor would give out when the engine runs rich, if the emissions come down then you have a faulty lamna sensor or wiring but if the emissions remain the same then the ECU is a possible fault. For more information on ECU testing click on ECU
The Range Rover is not exactly the fastest thing on wheels, although it has a big 3500 cc engine it is in a very mild state of tune, has a lot of weight to haul around, and the aerodynamics of a house brick. It also has a transmission system that saps a lot out of it too. Still it should go faster than the 60 MPH reported by our customer. On the V8 it is quite easy to have a few cylinders down on power a bit without feeling anything to horribly wrong, where with a 4 cylinder it would hardly pull you out the driveway. One of the first tests to run then was a power balance test where the ignition spark is removed from each cylinder in turn to see what the resultant engine speed drop is. At idle speed all was well, the engine speed drop was about the same on each cylinder. The picture changed though when we did the same test at higher engine speed under load - four of the cylinders showed very little drop in engine speed. This was a twin carburetor model Range Rover and the four poor cylinders were supplied by the same carburetor. So it was off with the suspect carburetor where it was found that a problem with the flow valve was restricting the fuel supply into this carburetor. After the carburetor was repaired and the rest of the tune finished the Range Rover felt a lot nippier, a fact confirmed by the owner who returned later that day with news that it would now do 100 MPH with no problem. I shouldn't think that the Police car that followed him in was too impressed by it's performance though.