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Dash doesn't light?

Discussion in 'Generation 1 Prius Discussion' started by ronlewis, Jan 18, 2024.

  1. ronlewis

    ronlewis Active Member

    Joined:
    Dec 5, 2016
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    Yeah, That's what I hoped when I got rid of that cable rig and installed the new battery. It's all clamped in fine now. Strong trunk light, battery has 12.7v, same in the Main JB. That's the pisser - after I did all that, it quit starting, lol.

    There is an ongoing issue - it's never lit up the dash or done anything in ACC mode. I can't make progress on that until I get it to stay powered up. I need to read codes, and guess my BAFX is fried, so I want to get someone to come by and read them, but every time it starts up, the next time I try, it's dead. That's the intermittent part I gotta fix.

    I know nothing about electricity, even the basic concepts. To me, it seems like there's a "master switch" that's shorting out, or something in front of the power flow going to all those systems that aren't working. But, it could be something else entirely, for all I know. It seems like it might be some component that is "timing out," or maybe a DTC finally erases from memory allowing the ECM to start again.

    It seems like it would be near the wrecked area - the passenger doors/pillar. The ECM and HV ECU and one more ECU are kinda over there, but no physical damage is visible. Otherwise just door locks/windows/seat belt type of stuff. IDK, could something as simple as a short on a window/door/seatbelt wire cause all this havoc? It doesn't seem like it, but IDK.

    I did swap in a known-good combination meter today with no change. I see 12v at it's connector so I know it's getting power, but it doesn't light up with key ON and the car didn't start. The power source page of the wiring manual shows the ECUs daisy chained on a closed loop off the Combo meter, so I thought that might be a likely suspect, or the ignition. .
     
  2. ronlewis

    ronlewis Active Member

    Joined:
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    Well, stupid me. Thought I needed to pull the key cylinder out to replace the possible fault, I just need to replace the electrical component of the switch. At this point, that looks like the most likely culprit...to me, which means it's probably not. But that's my next step.
     
  3. ronlewis

    ronlewis Active Member

    Joined:
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    And...it wasn't. LOL. Swapped in the known good ignition switch. Left the 12v battery connected overnight and it still had 12.68v today, so I don't think I have a parasitic drain. Checked fuses voltages before anything and no change - good at the Main JB, Dead at the IP JB, my Innova does nothing. Turned the key to ACC and those fuses do make Innova light up, but shows. 0.0v. Turn key ON, IP JB now has the 3.9V. Of course, no dash lights.

    None of that gave me much confidence, but it started, and ran fine. Let it run a minute, turned it off, and it started back up. Twice. Let it run until it warmed up and turned off, let it sit there several minutes, then put it in gear, and it drove just fine. Went around the block a few times, parked, turned off, and it started back again.

    At this point, I'm thinking the switch solved the intermittent problem and I was back to just the original problem of it being dead at key ACC. Not a big problem if it still starts and runs fine. I do some other chores for about an hour, rearranging cars in my driveway, go back to move it, and it doesn't start again. All the same deadness. The IP JB does show the 0.0v on my Innova rather than not showing anything or showing 3.9v.

    While it was running, I checked all the accessories, and the passenger front window isn't working, which is where the wreck was and those are different doors.

    I'm now thinking (I know, not good), that something is shorted to ground, and heating up some kind of relay/switch/diode/whatever that quits working. Later, after it cools off and works again, until it runs awhile and heats up again. Anyone know what kind of electrical component(s) can act that way? Relays?
     
    #23 ronlewis, Feb 11, 2024
    Last edited: Feb 11, 2024
  4. ronlewis

    ronlewis Active Member

    Joined:
    Dec 5, 2016
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    I know this is like a Quenton Tarentino movie with the plot jumping all around, back and forth. I'm grasping at straws over here.

    So, I checked the passenger door wiring I thought the paint guy had connected the harnesses back in for those doors, but it was just stuffed up inside the kick panel. Not sure why the back window worked because neither harness was connected. With the new ignition switch, I'd noticed the door open light on but kinda dim. It hadn't been on before unless the engine was running. Now, with the door harnesses connected, the light was bright.

    And, of course, it started right up. Same scenario, several times on and off. Then the last time, it threw the triangle right as I shut down. Turned Off, giving up for the night, and the door open light is still on. Then, it went off. So, checked all the doors and couldn't get it to go off. Is the hood and trunk part of that check as well?

    Anyway, last thing I noticed - kinda matches what I was thinking last post, that something is heating up and timing out. As I was sitting in the car, that door open light on, when I turned the key to ACC, that light and the clock stay on a few seconds, like they should (if door was open), but then fade out.

    I know none of this makes sense. But so far I've swapped all the relays, the ignition switch, and the combo meter for known good components and no change. I'm going to read up on the door open light and work on it tomorrow.
     
  5. ronlewis

    ronlewis Active Member

    Joined:
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    So, I looked through the diagram trying to match symptoms to harnesses, ground points, etc, that pass through the areas of the wreck. I found a couple of ground points that could fit the description, but could only locate one on the car. It seemed to be the most likely - real close to the point of impact in the wreck - but I don't see anything wrong with it. Still, I cleaned and reset it. The other ground point shows to be up under the dash, maybe behind the ECM, an area not as close to impact and more protected. Nothing else is damaged up there. Not sure if I'd possibly cause more problems pulling the ECM for such a small chance at the problem.

    Working theory: either loose ground or bare wire to metal short is heating a relay(?) that is setting a preliminary DTC, and (I need to confirm this) that when I turn the car on and off, thinking I'm just testing/confirming that it starts, I'm actually triggering the 3x starting-seeing-the-condition that's required to turn a pending into a priority code. That throws the triangle and then won't let it start back up without disco-ing the battery.

    Thought a mobile tech I know would be available to try to scan codes today, but I guess he took the day off after SuperBowling. I just I gotta buy another OBDII connector. I can't get the BAFX to work on any of my cars, and it used to. But, my brother bought one and we both had them with us on a trip and got them mixed up. Which is about when I started having connectivity issues. And dang, he's out of town. Anyone know of a good connector that works with Gen1s?
     
  6. ronlewis

    ronlewis Active Member

    Joined:
    Dec 5, 2016
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    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    Today's tease - car starts and I've turned it on/off multiple times, drove it about 3m. No triangles, no codes. You know that won't last.

    I borrowed a cheapo plug-in parts-store scanner from my mobile tech friend - his loaner unit. It's messaging said it was communicating with the ABS, Engine, and OBDII systems, but all it displayed in the results were two ABS codes - one of them a P1259 that had displayed in two of my other Prii that I'd checked with the scanner first. Not sure that one was not a leftover from those cars since the scanner settings stayed the same.

    Anyway, ABS codes seemed odd. So, I wanted to clear them using the scanner rather than the way I've been doing it by unplugging the battery, and then do a re-scan. I had the triangle and car symbols lit up, maybe the CEL too.

    Clearing in the "all of the above" (ECUs) mode on the scanner didn't turn off the lights. The scanner lets you clear by ECU however, and when I tried the ABS module - the only codes that had shown in the results - the lights still stayed on. I tried the Engine module next, and that shut them off. I did the OBDII for good measure.

    That's when I started turning it on and off, driving it around the neighborhood those 3m trying to get codes to reset. Recall that it had been resetting the triang;e/car just idling in my driveway and restarting 3-4 times. It's not been at least 45 mins, and I'm going to check it right now...

    And it still starts just fine. TBC, it's still dead in ACC, but in normal use, when you just hop in, start the car, and don't sit with only ACC on listening to the radio or something, it seems normal.

    This has been atypical up to now - me not having access to the codes. And these cars are always half-mystery because TorquePro gives me so little live data. But, what I'm wondering is if all this time there has been codes in the ECUs that do not clear with only a battery disconnect - this was in a wreck, so some safety sensors might have logged codes. Maybe it took a scantool clearing the codes for them to go away.

    Seems far-fetched, but we'll see how long it keeps starting and running normal.

    One interesting thing - I swapped over a known-good Combo Meter to see if that was the issue. I thought they were all the same and so didn't swap my original back in. As I'm driving today, I notice the odometer now says 224k - the mileage from the parts car. That's crazy, that all it takes to change the mileage on your car is swap over a junkyard CM from a low-mile car. I gotta think that's an aberration, something to do with why the CM has been acting flaky. I'm gonna swap my old with with 72k miles back over, lol.
     
  7. ronlewis

    ronlewis Active Member

    Joined:
    Dec 5, 2016
    938
    188
    1
    Location:
    texas
    Vehicle:
    2001 Prius
    Model:
    One
    You know it has to work this way. I have started this car and driven it around my neighborhood 10 times today. Around and around never going more than a few blocks from my house and the quiet neighborhood streets stopping restarting it over and over. Finally like this afternoon after letting it sit a while, I started again seems to be fine and I take off to the gas station about a half mile away because I'm almost empty. Get about a quarter of a mile away and it goes dead on me again. All the flickering lights and just dies. I was lucky to pull off of a Main Street into a parking lot. Now it's rush hour traffic and too busy to get somebody to come pull me the quarter of a mile home. And this is a dangerous neighborhood and it's almost dark. Not a fun way to end the evening. Every time I pull the disconnect the battery and let it sit plug it back in and it starts up and acts good but right now it only drives about 200 ft before it dies again. I don't know why it would drive around this morning all day long for several miles with no problem I don't know the difference. I have the headlights off. Anyway a long ramble because I'm on my phone you don't hear from me again the thugs got me