Causes for the Mitsubishi Check Engine Light

Modern vehicles are equipped with warning indicator lights for the most critical components that run a vehicle. There are lights for low oil and low fuel. Lights exist for low wiper fluid and low fuel. There are even lights that warn of low tire pressure. One light that causes concern is when an owner’s Mitsubishi check engine light comes on. This light can illuminate for a variety of reasons. The best way to find out what the causes the light to come on is to have a computer diagnostics test performed on the vehicle. A computer diagnostics test can be done free of charge at a local Auto Zone store. Here are codes that are most common with a Mitsubishi check engine light.

What is Code P1300?

This code indicates a problem with the Ignition Timing Adjustment Circuit. When this problem exists, the vehicle will have a low idle around 200 rpm and can sometimes have issues during acceleration. The vehicle should be taken as soon as possible to a certified mechanic. Early signs of timing issues should not be ignored. In the event a timing belt or chain breaks, severe engine damage can occur that will make the car immobile.

What is Code P1105?

The code P1105 is associated with the Fuel Pressure Solenoid. This code is a signal that alerts owners to the solenoid that is attached to the Fuel Pressure Regulator. When this code is generated, the terminals of the solenoid can be dirty or corroded. If dirty has built up on the terminals, simply clean off with a wire brush and reattach. If corrosion is the issue, replace the terminals. This fix doesn’t require a mechanic unless one is desired.

What is Code P1500?

The Alternator FR Terminal Circuit is what this code signals. One symptoms of a fault in the terminal circuit is if when driving the vehicle it shuts down. The vehicle will most likely not restart. This can be attributed to two main areas. There can be an open circuit inside the alternator itself, the FR terminal which is pin 4 at the green wire. The issue could also be a bad connection to the FR terminal from pin 41 that is connected to the vehicle’s electronic control unit. In either case, seek the advice of a professional to remedy the problem.

What is Code P1791?

When this code shows up on the diagnostics read out, there is an issue with the Engine Coolant Temperature Level Input Circuit. Driver’s who experience this will likely notice reduced fuel efficiency, rough idle and possible black smoke from exhaust pipe. There are two things that could be wrong here. The engine coolant temperature sensor is bad or the powertrain control module is bad. Both these sensors are connected to one another and troubleshooting will have to be done on both.

What is Code P1400?

The Manifold Differential Pressure Sensor Circuit is the instigator for this code number. This is one of the most important sensors for the D-Jetronic system. This sensor does not compile data for use by the electronic control unit in the same manner that other fuel injected systems do. The reason is that the D-Jetronic system does not have oxygen sensors that the ECU can receive data from. The Manifold Differential Pressure Sensor is a complex configuration. An in-depth analysis of this sensor can be viewed at

It is good knowledge to know the meaning of check engine codes and what the symptoms of these codes are. If the issues can not be self-repaired, the knowledge is already present to understand what a dealership service writer or other professional is trying to convey. Having the information before taking the vehicle in for service also protects an owner from being taken advantage of.