Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
Hi,When you unplug the crank sensor and measure voltage with the key on, do you have a 12V and a 5 V wire?
Thanks.So you are seeing on/off voltage (0v-5v-0v-5v) when you rotate the engine by hand and monitor the 5V wire?
Did anything recently happen with either the key (broken, replaced, different one being used than normal) or the PCM having been replaced?
If you haven't specifically checked that, please do so now by back probing the 5V wire and rotating the engine by hand clockwise with the key on. If there are any special circumstances regarding the PCM or keys please let me know and we will talk about the implications there.
Thanks.With regard to the key situation... make sure the "guts" are still intact and working (light flashes); if this key has a electrical failure it will cut spark/pulse.
Hi,With relation to the key.... the keyless function is completely unrelated on this model. There are two separate entities inside the key for the two functions, so operation of one doesn't really have anything to do with the other under normal circumstances. Likewise, the use of the unlock button etc doesn't affect the immobilizer.When rotating the engine by hand, you said they fluctuated.... we want to see very swift and solid switches between 0V and 5V... did you have fractional voltages in between or erratic behavior instead of solid switching back and forth on/off?
Thanks.So we most likely have good signal from the crank sensor, which means the PCM is waking up too.
You are 100% certain that you are missing both spark and injector pulse? As apart from a wiring issue the only real expectation here is going to be an immobilizer fault.
Thanks. The only things that would kill both the spark and the injector pulse would be the crank sensor... which we can fairly rule out if you have fuel pump operation, the PCM... which we can fairly rule out since it is powering up (They don't usually fail except catastrophically), a very rare wiring issue or the immobilizer.Given that the key has been physically broken for some time, I would suspect it is going to be that. There is nothing you can do with pin testing etc to test this... this is a logic response only, there is no voltage to measure or anything like that.
You are going to need to either get your hands on a spare key if you have one to try for comparison, or more likely get it to a dealer to have a key programmed for it. That will most likely clear everything up with your symptoms. They can check to see if the key you have is authorized first (or just reprogram it, if it will allow it) to verify 100% before purchasing a new key.
If you definitely do not have spark or fuel pulse but you do have fuel pump operation while cranking, I don't see anything else to suspect here.
The immobilizer shuts down the injector pulse first, then if the engine is persistently attempted to be started it shuts down spark. This is about the only way you can lose both at one time and not lose fuel pump operation. If the crank sensor was bad you would lose fuel pump operation, as with any problem with the PCM etc.I honestly see no other expectation here... and given the reliability of the immobilizer system, I would only expect a key failure. Nothing else goes wrong on these except the RFID chip inside the key is prone to fail.