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Thread: Bad ECM, license transfer?

  1. #1
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    Default Bad ECM, license transfer?

    Hello everyone! I purchased a used v1 and it has been working great. I have been chasing a misfire/backfire issue for over 2 weeks now and its driving me nuts!! I've looked at plug wires, plugs and valve springs but they all look and have tested ok. I haven't checked the lifters yet but I don't think that's the problem. The V1 I purchased came with 1 license and the original owner used this unit to upgrade to the V2. I am now thinking the ECM is defective. I can not connect with my Efilive cable and I keep getting an error that says "Efilive has detected that the PCM may not have a valid calibration" . It tries to connect and read the current tune but fails to connect on several attempts. It keeps trying and trying but ultimately says it can not connect with the ECM. I've also tried connecting with a hand held OBD2 controller and it does not connect either.

    If my ECM is bad what are my options for my license? Can It be transferred to the new ECM? Would I have to purchase a whole new v2 because of the upgrade? Thanks.

    Vic

  2. #2
    Forum tyhee Site Admin GMPX's Avatar
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    If the engine is running then chances are the ECM is fine as far as the communications side of things go. You haven't said what vehicle type this is, but given you have a V1 then it's probably LS1 based?
    We see so often aftermarket equipment causing major communications issues on these vehicles, iPod adaptors, XM Radio adaptors, pretty much anything that requires a connection to the vehicles communications bus. You probably need to spend some time isolating such devices if any of them are fitted and retry the read.


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    I have 1990 Silverado with a 408 ls based engine and is also turbo charged. It has a PSI wiring harness and the computer is mounted inside the cab. I accidently removed the ignition relay thinking it was the fuel pump relay so I could do the compression test. That's why I couldn't connect with the V1.

    I have a backfire/misfire issue and its becoming a headache. It only happens under a load to. I got it back from the dyno last month and it was running perfrect. The only changes I have made is a drop kit. I did have to weld on frame and I'm not 100% sure that I removed the negative side of the battery. I've read online and looks like it is pretty rare to damage a ECM from welding on the frame with out removing lthe battery but im sure it can still happen. I don't have all the grounds like a factory car so I guess that could be a possibility.

    I also found 1 of the wires that go to the crank sensor got burned on the dp. I was almost certain that was the problem so I fixed the burned section but I still have the backfire/mssfire issue. Could the burned wire being grounded or shorted out on the down pipe ruin the crank sensor or cause problems in the ECM? Any thoughts or advice will be greatly appreciated!!

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    Yeah I guess I can reflash my ecm with the file that was sent to me by my tunner. Do you think there could be something wrong with the current tune?

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    Joe (Moderator) joecar's Avatar
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    I was editing my response about flashing a known good tune file and somehow I lost it (fat finger delete, pretty ingenious for a moderator, eh...!!)

    I was also going to suggest to install V7 RC4 to see if that helped, from here: EFILive-RC-4-(April-10-2013)

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    Sounds good I will update in the morning and reflash the ecm as well. Crossing my fingers. What do you think about the welding of the frame or the wires to the crank sensor being burned and grounded to the exhaust. Could that make the sensor go bad or cause the ecm to act up?

  7. #7
    EFILive Developer Site Admin Blacky's Avatar
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    Can you connect with the V1 long enough to retrieve any trouble codes? If so what trouble codes are set (if any)?

    The "Does not contain a valid calibration" message is generated by the PCM. Its the PCM's way of telling the Scan Tool that its internal checks have failed and the calibration is either corrupted and/or incomplete. The only way to correct that is to complete a calibration re-flash successfully. When the PCM is in this state it is what we call dead-poll mode. When an LS1 controller is in dead-poll mode it transmits a "dead-poll" message about 4 times per second. You should see the orange OBD LED on the FlashScan V1 device flashing about 4 times per second when you connect it to the vehicle. If it is flashing consistently at 4 times per second then it is almost certainly in dead-poll waiting for a successful re-flash.

    When it is in dead-poll mode the engine will not start, so if the engine is starting then the PCM is not in dead-poll mode. There may be some other wiring issue making the Scan Tool think that it is getting a dead-poll message from the PCM when the PCM may be perfectly fine - just unable to communicate clearly with the Scan Tool.

    Regards
    Paul
    Before asking for help, please read this.

  8. #8
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by vic View Post
    Sounds good I will update in the morning and reflash the ecm as well. Crossing my fingers. What do you think about the welding of the frame or the wires to the crank sensor being burned and grounded to the exhaust. Could that make the sensor go bad or cause the ecm to act up?
    When welding on frames/chassis/body/exhaust I would be very cautious, I would disconnect battery and unplug all modules (yes it can be quite a bit of work) and also unplug the O2 sensors (if welding on exhaust)... think about this: the welding current is sufficiently high enough to jump a 20mm gap (from the filler rod to the workpiece)... sure it directly seeks the ground clamp... but what if the ground clamp is making poor contact, then the current has multiple other easier paths to go.

    Were CKP sensor wires burned from their inside (large current shunting to block seeking ground) or their outside (heat from exhaust)...? Sound like maybe the CKP sensor is fused or degraded, this will prevent the PCM form running the engine properly (if at all).

    You would have to perform a few more tests to determine if the PCM has suffered... if you short its outputs, they can survive some amount of large current for a moderate time, but then they may be weakened and may pop (usually the PCM sees no voltage change on these outputs and so usually throws a DTC).

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