Mitsubishi Diamante Maintenance and Repair



  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    There's a difference between Traction Control and Stability Control.
  • bitsofmishibitsofmishi Member Posts: 1

    We have the exact same problem - accept it was stinking hot and a/c air only came through the door side vents. There is a small unit under the right hand side of the steering wheel. When we changed the air to fresh it clicks about 7 times then nothing happens. What has happened is that the gear in their has got jammed. Ended up taking the front cover below steering wheel off, and played with the mechanism, now it is open all the time - which is better than having no air. Hope this helps.
  • jabussejabusse Member Posts: 1
    the tcl control box is located behind and below the radio.
    The problem you describe is usually caused by either the vent control valve or the vacuum control valve located on the firewall above the brake master cylinder. The vent control valve has one hose on it and the vacuum has two. the top hose on the vent valve is tagged green dash on the vacuum line coming from the vacuum control valve (bottom pipe. and throttle body. The top pipe on the vacuum control valve is blue dash. These get old and suspetable to heat. You can spray them with freon to cool. The engine code may be p1101 and the TCL code is 72 or 73. Best to replace them both (assembly costs about $130 from the dealer. Junk yard valves are old and probably thermally sensitive too. If your diamante is 2001 and 2002 early, there is a filter fix that is contained in a service bulletin. But I'd try the valves first. The most sensitive is the vent valve. To clear the fault you might need to disconnect the ground terminal from the battery for over 20 seconds.
  • kevinsdiamantekevinsdiamante Member Posts: 7
  • kevinsdiamantekevinsdiamante Member Posts: 7
    just wondering if any of you have experienced an intermittent missing condition with your Diamante, my 97 D misses sometimes when cold and then stops when it has warmed up, sometimes just the opposite...plan to replace the plug wires,rotor,cap again just the same..
  • maxoutputmaxoutput Member Posts: 2
    I have read in a lot of forums about how to replace a heater core in the diamante. I have just replaced mine so i know how it is done and it only takes a couple hours to do. You dont have to remove the dash, as many think but you do have to remove the, glove box, heater blower and air con to get to the heater core. it can be a bit fiddley with some of the bolts but it can be done and is quicker than leaving it a a dealers :sick:
  • protech_auto1protech_auto1 Member Posts: 3
    Customer calls me to check out her car. I dont do alot of diagnostic repairs on Mitsubishis or other vehicles with CIS/Bosch systems.....I find a dead battery, so replace that, then test the alternator and found it making bearing noise too, so replace alternator. A week later the starter catches fire internally and melts battery cable and oxygen sensor wire that wasnt hanging right.

    Replace the starter under warranty from penny pinchers auto parts and manager wont file labor claim on my behalf and he has a history of selling crappy parts. Picked up battery cable from dealer.
    Anyway....start and stop the car 20 times on a 12 mile test drive and it runs great but the sensor wires were frayed and i replaced the sensor with an after market part. Replaced the first sensor because this car has california emissions and we didnt know. I did find that this oxygen sensor was cross threaded into the pipe so i cleaned it out with a tap and then cranked down the sensor as best i could. i dont believe that hole is a problem.
    Car has some issues but she claims she put $20.00 in fuel into the car that morning the starter failed, so i cant imagine its out of fuel but the fuel gauge is stuck on 1/4 tank and im not sure what is causing that yet.
    The throttle body was cleaned while i replaced the starter and this car ran good during that test drive. This was when the air box was removed. I replaced the oxygen sensor and it will start and stay running. If i feather the foot pedal above idle it holds RPMS. On cold start up it seems fine for a second and the RPMS go up over 1500, then stall. I Checked all vacuum lines and only took off the air filter housings and reinstalled them. I did find a pinhole in the fuel regulator hose, so cut that off and reinstalled the hose. No change there. The only connector to the air filter housings is the mass air flow sensor and its working. there is no engine codes, it just starts and dies....
    You should know that when i installed the new battery and alternator, that 5 fuses under the hood were burned out and 3 inside the interior fuse box were burned out too. A 120 amp master fuse was blown as well. None of the options were working and i installed new fuses and nothing has blown since. I cant imagine why all the options quit on this woman and i spent many hours checking it out for her. She doesnt trust the car anymore and GAVE ME THE CAR for my time into it because it has several issues wrong in other areas and i will fix them and drive this car.
    oHHHH where is the fuel pressure testing port please?
    I dont believe the fuel is low enough to make this stall. Maybe ill tote 10 gallons to it anyway. I am leaning toward maybe fuel pump failure or fuel pressure regulator.
    Thank You for your time.
  • jibyojibyo Member Posts: 2
  • jibyojibyo Member Posts: 2
    Can I remove the ash tray and install a head unit where that used to be? I have the touchscreen with the tape deck and apparently you can not remove it, runs the gps and heating ect.

    I'm new to doing this sort of stuff on cars but im good with this sort of stuff out of cars...
  • protech_auto1protech_auto1 Member Posts: 3
    Last November I replaced alternator, battery and both battery cables, (cable from dealer). Prior to this some mechanic replaced one front downstream 02 sensor but replaced the wrong one and code stayed present.
    When the starter caught fire because it was a cheap part that was put on by old mechanic, it failed. Everything was going fine after the electrical stuff replaced.
    Driving along and car quits, battery died from trying to start it. Got to vehicle later in the day and nursed it home on the freeway at higher(2000 plus) RPMS. Pulled same 02 code for sensor on back bank after the cat. Replaced front sensor because starter caught the wires on fire when the starter burned up...this front sensor is the one the mechanic replaced and he installed it cross threaded. SO i seen smoke coming from the hole and took it too exhaust shop who replaced the bung and installed the 02 sensor again with very few threads left but it worked for now. Smoke problem fixed. Had airbox off vehicle. Code for sensor was still stored for back bank after cat, so replaced it but accidently installed the connector back words because the new sensor appeared to be deceptive on how its installed. Found this problem out and reversed the sensor to normal. Code didnt set though. No codes but on start up the idle goes to 3200 rpms. SO i thought maybe i had a bad air meter and unplugged it and the idle went down, so got a used one from parts yard and no change, so i feel that ruled out the meter causing the problem. I know its possible a used part can be bad but this part came from a good facility with a good reputation of stocking and selling tested parts. Old air meter would not let car idle at all.
    Installed the air meter and put the air box back in. Did break one of the plastic tabs(worn plastic junk) where the lock down for the air box holds the air filter in place but this is before the air meter, so this should not affect the meters reading.
    I cant find a chart that tells me what the parameters for all the sensors that are on this car and what they should read on the scanner screen.
    I dont find any blown fuses.
    There is a plunger type device on the backside of the throttle body area where its not anywhere near the other end of what would appear to make contact. I dont even know if this is an issue or not.
    Like i said before all was driving down the road and it just stalled. I think it was ran out of fuel so i put fuel into get it home to be sure that wasnt it. The gas gauge I think.
    The car sat for a couple months while out of Arizona and the battery died. Any chance the computers not relearning itself properly and causing this. I dont find any leaks by listening and looking for vacuum leaks.
    There is also a hole in the flex tube of the exhaust but I dont think this is an issue.

    Second part to this.....
    Finally got time and used utube...I did not do compression test because problem isnt with the engine, so i feel I am okay to say I dont need it checked. The car is running good its just something I have done to cause this high idle. I drove the car down the street to carwash and it runs good, just high igle and idle drops a little under 500 then back up.
    I removed the air sensor under the throttle body and cleaned it wih mass air sensor cleaner...this turned off the oxygen sensor code that was setting. When removed it came to thought that I used brake parts cleaner to clean the throttle body while back and I didnt know this system enough to realize this sensor has the air ports inside the mouth of the throttle body, so cleaned it all again this time and installed the sensor.....not sure if that brake cleaner damaged this sensor because i dont usually do engine performance repairs on Mitsubishi and send them away to a dealer for diagnosis because its cost effective. Now than, the air boxes air filter has both of the clamped pins broken to hold it in place but this is before the air meter so I dont think this is an issue but you could correct me if wrong. The car starts nicely and runs nicely so I dont think fuel is an issue, the wires and plugs were put on recently and there is no engine miss or rough idle...just that dang steady high idle. I took 3 snapshots of the system with my otc nemesys, so im in the house now trying to figure that out on the laptop what sensors are reading wrong. thank you
  • protech_auto1protech_auto1 Member Posts: 3
  • Kirstie_HKirstie_H EdmundsAdministrator Posts: 11,126
    Hi there -
    Diamante owners are rather scarce these days. You will probably have better luck going to our Maintenance and Repair board and posting in one of the more general discussions near the top of the list. You have more mechanical expertise than most people, and so do many of the members that hang out there, so it'll be a better place to get feedback... and to find other members who know what YOU are talking about!


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  • edster1983edster1983 Member Posts: 1
    Does anyone know the location of the ASD relay for fuel pump cut off switch.  I have a 2000 mitsubishi diamante LS 3.5 with traction control. For some reason now fuel pump is not getting power.  Have a tester switch in which I put in place of fuel pump relays.  The fuel pump works as do the fuel injectors up front. My fuel pump is under the back seat cushion in the center. I've replace a lot of parts thus far. When the new relays are in the fuel pump makes no sound.  According to other forums if u by pass and send power to fuel pump if makes sound then thepump and wiring is fine, so then the auto shut down switch is malfunctioning. ASD RELAY but no forum says it's location.
  • PF_FlyerPF_Flyer Pennsylvania Furnace, PAMember Posts: 9,372
    Do you currently own a Mitsubishi vehicle? If so, a reporter would love to ask you a few questions. Please send a note to [email protected] by end of day Thursday, November 30 if you'd be willing to chat. Thanks!
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