2003 Mitsubishi Diamante: check engine light

Filed Feb 16, 2010 · Engine, Visibility · 60,000 miles · MA

Anti-freeze leak on carpet passenger side near firewall fogged up windows check engine light comes on and off due to the leak the ecu started working awful.

Filed Apr 16, 2008 · Engine, Transmission · 78,000 miles · TN

I own a 2003 diamante mitsubishi. The problem started with a check engine light coming on, fogging the window with a fowl toxic smell then the car would not hardly move out gear. I was told that the car's heater core leaked onto the computer which caused the transmission relay to short out do to the computer failing. The computer was still under warranty at 78,000 miles but I still had to pay for the new computer system because I was told that it was the heater core that caused the computer to fail. This is such a poor design! The computer should have been protected in such a case...funny thing it is now that I have had to replace a heater core, a computer and a transmission relay at a cut wrenching cost of $3,675.58. I wrote a letter to the president of north america mitsubishi that the heater core should be a recall but to no avail. I have all maintenance records on the diamante so that was not what caused this heater failure. I do have the computer that was replaced. It is now april and the check engine light has come back on...now what? Aj

Filed Apr 7, 2008 · Engine, Visibility · 20 miles · CA

I have 2003 mitsubishi diamante. My "check engine" light came on, so I took it in for service, and my heater core was leaking on my computer...now it's going to cost me around 3,500 dollars....this is a very flawed design. There should be a recall on this item.

Filed Jul 16, 2007 · Body, Visibility · 33,000 miles · NJ

For the past two years our car has had a very pungent fowl smelling odor when the air conditioner or heater is engaged that has gotten progressively worse. I took the car for repairs prior to the termination of the warranty and was told (by the dealership) that they did not notice a smell, and there was no problem. Six moths ago the car began to run hot and I took the car to our neighborhood mechanic. Under pressure he noticed a small leak in the coolant piping and replaced a section of pipe ($150.00). I asked if this could be causing the odor (as mentioned earlier and he stated maybe, or it could be the heater core).within the past two weeks the 'check engine soon' light has come on and upon checking the message and inspection of my car I've been told the heater core needs to be replaced. My neighborhood mechanic was at a loss because told me it was very odd for the heater core to fail so early in a car. I've checked the internet and have come across hundreds of people in the same situation (with mitsubishi's). I am very upset with the fact that the mitsubishi dealer may have lied to me (when the car was under warranty). I asked for multiple items to be fixed (under warranty) and they refuted every request. The heater core will be replaced within two weeks.

Filed Apr 10, 2006 · Visibility · 52,000 miles · LA

Steering wheel began to shake and visible fumes began entering vehicle through air vents. There was a strong stench of anti-freeze. Check engine light was on and vehicle became hard to control. After taking car to local dealership, I was immediately told, even before an inspection was done, that the heater core on vehicle had a slow leak that over the course of "several months" that eventually leaked on to the transmission electric box and shorted out the entire system. It seemed obvious that this was a familiar issue with this particular vehicle. I was originally given an estimate of $3,300, being that the vehicle was past its warranty period. After several calls to owner of dealership and doing research on this vehicles complaint history, the price was reduced 3 separate times, finally costing me $880. Apparently, mitsubishi headquarters picked up the cost of the parts, leaving me to pay labor charges. The mechanic handling the repair stated that due to "poor design" on this particular vehicle, and even with our regular maintenance checks at the dealership, this problem cannot possibly be recognized or diagnosed in its early stages until it has caused extensive damage. Needless to say, this will be my last mitsubushi.

Filed May 19, 2004 · Brakes · 6,000 miles · NY

I have a new 2003 mitsubishi diamante, which Ive taken back to the dealership 3 times now with the same two issues: the front breaks make noise and my stearing wheel vibrates when I brake and the check engine service soon light keeps coming on.*ak one of the dealers employees told me that the brakes issues was very common as sometimes the cars sit for a long time in a lot before they are sold. This does not make feel safe driving this vehicle at this moment. The dealer will fix the light and brake issue assuring me that its all fine now but the problem keeps coming back. Ive placed a call to the mitsubishi motors company about this and they told me that they need to review the case to figure out what to do about it.