22nd Jun 2011, 07:12

The TCL light and service engine light shouldn't be related. Also the TCL is not related to the catalytic converter. If you have got a traction control failure, this shouldn't much of an issue, and the car shouldn't fail an inspection.

27th Jun 2011, 14:38

What ended up being wrong with your car? I have the same issues and would like to attempt to fix it myself.

29th Jun 2011, 20:08

TCL relates to anti lock braking system. A wheel sensor maybe bad. Service light means you have OBD II codes which indicate where a problem may be. Sometimes a tune up will eliminate the problem. New plugs and O2 sensors and plug wires sometimes eliminate these codes. What codes do you have? Resetting or clearing codes does not fix the problem.

16th Jul 2011, 00:12

I have a 2003 Diamante VR-X. It's a wonderful car. We have 103k miles and just did the water pump, timing belt, full tune-up and valve cover gaskets. My question is this. The horn doesn't work at all. It won’t work if you press on the steering wheel or when you arm the factory security system and set it off. The horn DOES work if you jump a hot wire to it, so the horn is and can work. Also, all fuses and relays are good. My local mechanic today told me he thought it had to do with the factory security system, but it seems to work fine except for the horn. The security light flashes on the dash, the lights flash if the alarm gets set off, just no horn. Any ideas would be great! Thanks everyone!

2nd Aug 2011, 18:41

The anti-freeze smell, as you probably know, is caused by the o-rings. The test is to look behind the passenger side carpet near the center console; on the firewall you should see green soot. Usually there is not a leak, but just gas that deposits on the carpet. You should also build and install a plastic shield over the ECM. That is right below the o-rings to the heater core. Just reach in from the driver's side and place your hand on the flat part as far forward as you can get on the center console near the firewall. If water gets into that box, you are talking real money. The o-rings cost about $3.00, but to install them you need to pull out most of the dash. Very hard and complex, and getting it back together is a real challenge.

24th Aug 2011, 22:44

I'm having the same problem as far as the TCL flashing... did you ever find out what was wrong?

23rd Nov 2011, 21:24

I've got a 2001 Diamante with 81,000. Horn stopped working 4 years ago, and after checking fuses, relays and the horns; just gave up.

Now I've got the leaking heater core and computer problem. It's difficult to get reliable information on these cars. Right now, I'm trying to find out if the ECM must be changed with the immobilizer or not. One mechanic said the ECM would not require flashing (reprogramming) if installed with the Immobilizer. This turned out to be not true. The car must be re-programmed with the existing key.. At this point I have more questions than answers.

1st Mar 2012, 23:32

Hello all. I'm the owner of a 2002 Diamante LS, bought in 2005 with 28k from a Carmax. Thank God I decided to shell out the extra $$$ for their extended warranty, because I would have been absolutely "SOL" without it.

1. 45k, heater core went out.

2. 48k, O2 sensors went out.

3. 57k, shifter went out.

4. 64k, tranny dies (the 1st time), Aamco refurbishes.

5. 70k, antenna dies, sunroof dies.

6. 104k, tranny dies (2nd time). No longer under warranty, I shell out $950 for a used 80k tranny and $500 for the install.

7. No more than 2 months later at roughly 108k, the tranny dies for the third and final time.

I kept my car up to date on everything, didn't drive it like a race car, didn't chirp the tires every corner. Drove it like it was going to be the last car I would own.

These cars are simply lemons, and should have been recalled with all the issues that "EVERYONE", regardless of the owner, has.

Now I just hope that I can get $500-1000 for my car, and the refund on the $950 tranny, so I can afford to buy a Honda Civic that I'll be able to drive until the day I die.

DO NOT PURCHASE A MITSUBISHI DIAMANTE!!!

14th Apr 2012, 16:58

I have a similar problem, the "service engine soon" light comes on intermittent. Should I be concerned?

22nd Apr 2012, 14:00

I bought a 2002 Diamante brand new. It's still running and has already 180,000 miles. I had most of the problems mentioned here.

The heather core broke right after warranty expired. The dealer replaced it, was expensive.

The antenna mast also broke a year after, I ordered a replacement on Internet, replaced it myself, worked perfect, still there.

At around 140,000 there was an smell of motor oil inside the car, the battery did not charge. The dealer found the head gasket was leaking oil and dumping it onto the alternator. This fix was also expensive.

Since brand new the brakes never worked properly. They just started working as they should 4 months ago when all 4 rotors were replaced. The ABS light was almost always on, and still is; I did not care. I replaced the struts, front and rear the last December, 160,000 miles. It really made the difference, feels like brand new.

I am pretty sure that it wouldn't last this long if I wouldn't have replaced the timing belts and flushed the transmission fluid every 60,000 miles. It had only 2 tune ups: one at 90,000 miles, and another one at 170,000 miles.

It wasn't that bad, I loved its lines and shapes, it's impressive. But, I would not buy another Diamante again.

27th Apr 2012, 23:21

I have a VRX 2002, also with exact problems. I would not buy or recommend a Mitsubishi to anyone.

28th May 2012, 20:08

I know that this is an old post, but I have a 02 Diamante, 115,000 approx miles. This problem just happened to me today with no warning at all. Have you found out what is causing this?

25th Jul 2012, 09:37

I have a 2000 Diamante, and my engine light has been on for about two years.. the code references to an O2 sensor. Finally decided to take it to my mechanic, and after replacing 2 of the sensors, the light is still on with the same code... what does this mean? And how can I get it fixed? My mechanic said that it could be the ECM itself.. also the ABS and TCL lights are on, and have been on for a while as well.

8th Aug 2012, 16:54

I bought a used Mitsubishi Diamante 2004. 2 months after I got it, the transmission went out, and that was at 60k miles.

Then I got all new tires and rotors. I have to get my brakes replaced and rotors at least once a year.

Now I have 180,000 miles, and the TCL and engine light have come on. The engine light because of an O2 sensor. The TCL, I'm not worried about it, because it's causing no problems.

I've also had a brake flush and a transmission flush, wow!!!

It's so expensive to have this car, but I love it. I guess because when I bought it, it had a built in DVD/Navigation system; how can you resist :)