420A TCM probs

[Dsm13]

I'm back. So I took my 95 non turbo eclipse to a mechanic and claimed that there was just a short in a wire and he fixed it. But it wasn't fixed. So then he changed his opinion to the tcm is bad I'll get another one for you. It's been almost a week and he hasn't been able to get one for me. But I came on here because it's getting worse and I'm wondering if all these other problems could be related to the tcm.

The panel lights flicker alot. The sterio will just turn off then immediately turn back on. Sometimes the engine feels hot after driving sometimes cold after driving. Starting up the car while the engine is warm is horrible. Barley starts, almost acts like dead battery, but battery seems fine.

 

[1g Cam]

I doubt it would have anything to do with your radio.

 

[Dsm13]

I don't get it. It's like everything electrical in my car runs through my tcm. Everything is f***ed up because of it.

 

[PlanZero]

Don't start new threads for the same problem. On a 420a the TCU couldn't be any easier to reach. Its right under the hood. Any local junkyard should have a few. Swap it out and see if there's difference. I assume you changed the battery terminal connectors already if you were having electrical issues. You're talking about shifting in your other post; I hope your not manually shifting a 20 year old automatic transmission. In my experience that's a sure fire way to destroy it.
Also, you're best bet is to stay away from mechanics. You'll be broke in no time. As everyone on this forum can attest, there will be many times where you'll chase down problems and throw away money on parts trying to isolate the cause.

 

[Dsm13]

Ummm. I wanted to post in the same thread, but your rules say no bumping. Stay consistent. Do you want new threads or bumping. You can't have it both ways like a spoiled brat.

 

[Lou98GSX]

Get your electrical problem fixed first then see if your trans still acts up . Like it was said before check your battery connections and grounds and make sure that your alternator is charging.

 

[Dsm13]

Well the alternator looks really clean and new compaired to other parts of the engine. It looks like there's a ground bolted right off the positive terminal. I don't know it's very inconsistent. Sometimes it acts better and sometimes worse. Like today it Stalled after I was trying to get into a space and shifted from drive to reverse a few times.

 

[Skyline-Tweak]

My 95 420A Talon gives me issues all the time. As far as the lights flickering and the radio cutting out, I'd like to say check the alternator. I bought an new alternator from AutoZone and 6 months later it was shot. I have a subwoofer and it was drawing too much power. The first sign was the radio would cut out. Then the dashlights began to go. Most cars are wired so that the important things like headlights and tail lights will be the last to go for safety concerns. As far as shifting goes, when mine was automatic it went into limp mode which is a completely different issue than what you're describing. But I was told it was the shift solenoid. You could check yours and see if that's your problem. I just got sick of it and swapped it to manual. Stalling because of an electrical issue is related to idling malfunctions. When my alternator went, so did my idle. I guess the sensors weren't getting the right amount of current flowing to them and threw them off readings back to the ECU. I could also imagine the off readings is what's making it hard to start by not knowing the correct air/fuel ratio.

 

[Dsm13]

As weird as it sounds I believe that somehow the tcm is f***ing with everything. Today the car was in limp mode and everything shut off at a stop light. It was like a stall, but felt a little different. Then everything pops back up and the car is out of limp mode. Hopefully we'll see soon. The part should be in soon and the mechanic will work on it next week.

 

[ThunderChild]

It sounds like you have a a grounding issue. Check and preferably repair/replace all the grounds you can.

I was getting intermittent gauge and light flickering on my mazda. Had horrible, rusty grounds all over. After replacing them and fixing a couple that weren't just straps, no more flicker.

At worst, you spend a couple bux and an hour or two ensuring you have a secure current flow path to-and-from the battery/alt.

Also check your ecm/tcu grounds, as well as any harness grounds in the footwells.

If that doesn't fix it, you're harness may be internally shorting between a couple wires, so ud want to check for cracks, cuts and oil soaking.

Gl.

 

[Dsm13]

Some of the grounds are real easy to see. Like one is literally screwed in right next to the battery. But I would have no clue were to look all over the car for groundd. Just get it on jack stands and look for dirty wires screwed into the frame and shit?

 

[Dsm13]

Ok. I swapped out my tcm and the transmission is out of limp mode and is shifting smooth and normal. But there are still some problems. The speedometer is way off, I would guess I just need a new speed sensor. And also the car is now acting like there is a Rev limiter on it. It won't go over 3000 and shifts sooner than it normally would, and once it hits top gear it usually settles around 1500. I didn't believe that tcms come with any type of Rev limit program. Any suggestions are welcome.

 

[ThunderChild]

there are a few all over the engine bay.

look for wires going directly to the chassis or frame. the only couple under the car should be from the exhaust to chassis and possibly around the fuel tank/pump area.

generally, from the engine block to battery, block to chassis, alt to chassis, exhaust to chassis and of course battery to chassis. the rest of the grounds will be close to the wiring harness inside the engine bay and inside the cabin. just follow the harness and look for wires coming out, and being bolted or screwed to the frame.

any ground connections you should clean and repaint after repairing.

you could also look up an ecu pinout or wiring harness diagram and look at ground locations.

 

[X2M7NOZ]

Rpm limitation only comes from the ecu last I checked. Did it solve your power cutting in and out? And if your mechanic messed with the vss its very possible he threw it out of calibration, recalibration should fix the speedo. Unless the sensor is indeed bad but i see no reason it would be, but stupid things do happen. As far as this rpm limitation goes, have you tried getting around it? Do the rpms stay in roughly the same place or do they bounce? Have you tried using 1st over just drive? The more specific you can be the better.

 

[Dsm13]

I have no clue what was going on with my power, but my Battery died and I just recharged it and everything's fine. Seems odd with a new battery and alternator.

The rpms don't jump around except for whenever I stop it jumps from 1000 to 1200 car moves forward a little, then drops to 800.

When I'm driving the rpms usually stay around 3000 in the high and 1500 in the low.

The only other thing is that when I switch from park to drive it'll jolt, which I thought might be tranny mount, but whenever I go from Park to reverse, or reverse to drive it's fine.