Electronic Diagnostics: Mitsubishi Mirage 2 1.2
Tracing and fixing faults in electronic engine management systems Mitsubishi’s compact Mirage seems a good buy for cost-effective motoring, but what about its diagnostic aspects? Kim Henson and Edward Haggar take a look.
Mitsubishi’s current Mirage 2 is actually the sixthgeneration model, worldwide. It was introduced in 2012, effectively replacing the Colt lineup, although the Mirage name had previously been applied to the company’s small hatchback produced from 1978.
The Mirage 2 was developed with efficiency in mind, and features extensive use of lightweight high-tensile steel in its body construction to make the car as light as possible. It is also highly efficient in terms of aerodynamics and is powered by a frugal three-cylinder 1.2-litre petrol engine, which delivers CO2 emissions of just 96g/100km, helping it fall into the lowest possible road tax band.
Although compact, the car incorporates five doors and five seats, and is wellequipped in terms of standard-fit safety items and everyday conveniences. In our experience, the Mirage is among the best of the modern compact cars and has very few inherent faults.
Our car is a 2014 example and Edward Haggar is our guide to this model.
Preparation
At the outset, establish when the vehicle was last serviced and, if in any doubt, carry out a full service, renewing the spark plugs, filters and engine oil, then reset the service lamp (see Service lamp
reset procedure on page 88). These Mirages are extremely easy to maintain at home, with even jobs such as replacing a clutch being straightforward. Engine oil and filter changes only require a 14mm spanner or ratchet and socket, and the spark plugs are readily accessible once the air filter has been removed.
Given regular maintenance, these engines will clock up mega miles without problems. However, as with many compact cars, one aspect that is potentially troublesome is that these Mirages have a habit of rapidly wearing out the front brakes and showing signs of pitting and corrosion on the brake discs. Nevertheless, brake components are readily available and relatively inexpensive.
Fault 1 ECU SOFTWARE PROBLEM
Our first fault with this Mirage happens during cold starts. The engine will deliver a knocking noise and, if left to its own devices, potentially fail catastrophically. In most cases, the problem will have been dealt with via a recall from the dealer.
Although the symptoms sound like a mechanical failure, the knocking is actually due to a fault with the ECU software causing over-fuelling. Diagnostic work should start with confirming that there is no mechanical failure, then carrying out a diagnostic check, although it’s likely that no fault codes will be stored because the ECU believes that what it’s seeing is correct. It’s worth checking with a dealer if the recall has been done, and getting them to check the level of vehicle software.
Fault 2
ENGINE FLOODED WITH FUEL
Our next fault is actually the result of driver error. The vehicle will crank and possibly try to fire, but won’t start.
The problem is down to the engine being flooded, to which it is prone. It is likely the driver will have moved the vehicle a short distance and switched off, with the engine flooding with petrol when a restart is attempted. This is similar to an older vehicle being started with the choke pulled out, resulting in excess fuel flooding the spark plugs.
The solution is a simple and cheap fix: simply remove and dry the spark
plugs, then refit them, torqueing them to 25Nm. Then, with the accelerator pedal floored, remove the fuel pump fuse and crank for 10 seconds. Refit the fuse and watch the engine kick into life. There may be a bit of excess smoke due to unburnt fuel, but this will clear quickly.
To avoid the problem, every time the vehicle is started, it should NOT be turned off for at least a couple of minutes.
Fault 3 AILING IGNITION COIL
This fault is a misfire – the engine runs roughly or is even undriveable, and the management lamp is illuminated. The fault lies with the ignition coil.
Make a full diagnostic check of the ECU and you are likely to discover fault codes relating to the problem cylinder. These engines have only three cylinders and need to operate on all three. Fault ‘P0301’ refers to number 1 cylinder, ‘P0302’ to 2 and ‘P0303’ to 3. It’s worth swapping the coils from one cylinder to another as a quick confirmation of which one is faulty and, if possible, to ’scope the cylinder trace. It goes without saying that the spark plugs must be renewed after sorting out the duff coil, ideally renewing all three coils at the same time.
Fault 4
UNUSUAL HEATER DESIGN
This fault is only really noticeable in the winter. When the driver operates the blower fan with the heater on, it seems to be less effective on the driver’s side, taking ages to clear the screen. Although you might suspect a disconnected heater flap, the trouble is down to poor design for right-hand drive Mirages; the set-up differs for left-hand examples.
There is no permanent fix, but you can apply Rain-x Anti-fog to the screen, although this means it could take longer to clear if there’s thick ice on the glass.