Ford Reviews

On this model, the sensor in question is located on the crankcase (not the cylinder head as many are). You’ll find it on the driver’s side of the crankcase, below the intake manifold. Replacing it involves removing the old one by screwing it out, and screwing the new one in. But there’s a bit of a process for this, and if you’re not familiar with this type of job, it’s probably one for the experts.

The sensor is located between cylinders three and four and it’s located pretty close to the manifold. The good news is that you don’t need to remove the manifold to access the sensor; you can get to it by going into the engine bay through the wheel-well.

Don’t forget that you’ll lose some coolant in the process, so that will need to be topped up with the correct type afterwards. Remember, too, that the new sensor won’t work unless you correctly reattach the wiring plug that connects the sensor to the rest of the car. This area can be pretty grimy and muddy in a vehicle like this, so cleaning everything off first is a good idea.

You’ve probably already figured out that the two codes mean you potentially have two separate problems, but either one of them could cause your car to switch to limp home mode. In any case, they both need to be fixed.

So, let’s start with the PO118 code. This suggests you have a faulty engine coolant temperature sensor. When this fails, the computer isn’t getting the information it needs to know whether the engine is cold or warmed up. As a result, the fuel-air mixture will be all over the place and the vehicle will possibly use more fuel and run poorly as well as being hard to start in the morning.

The other fault code you’re seeing, PO489, is to do with the engine’s exhaust gas recirculation valve. This valve channels some of the engine’s exhaust back through the combustion chambers to reduce tailpipe emissions by burning the same gasses twice. Your car’s computer will be constantly opening and closing this valve, but it’s an electrical signal (from a sensor) that tells it when to do so. If this sensor has failed, that information won’t be getting sent to the computer and the check-engine light will come on.

Both of these faults will probably be fixed by replacing the sensors in question, but until they are replaced, the car will continue to throw fault codes and switch to limp home mode.

Your mechanic is spot on. As far as the warranty laws in this country are concerned, there’s no difference in having the vehicle serviced by a Ford dealer or by a qualified independent mechanic. If there’s a problem down the track, it won’t matter who serviced the vehicle; a warranty claim is a warranty claim. Your peace of mind should be no different either way.

The only difference might be if Ford looks more favourably upon your case considering you’ve been a loyal customer and had the servicing done by your dealer. But don’t go to the bank on that, as it’s by no means a legal requirement, nor a widespread occurrence.