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hello to all I have a recurring problem for some time, I have a fault 16985 internal error checksum memory, I specify I am in stage 1 e85, I have tried several manipulations other ecu same, other flash cord Same mpps, kess , in the rosstech list it mentions low voltage, I have a new alternator but my battery which is 2 years old at most gives strange signs of voltage drop at start-up 8V and this is often where the fault appears, forcing it to be reflashed 'ecu I don't know where to look anymore I have 12.5V when stationary and 14V with the engine running, small indications the engine in some cases has trouble launching it

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attached is the link of the video where we see the instrument weaken at start-up battery 100ah 800 or 900a of memory


https://youtube.com/shorts/qxFWXUJ0u2E?feature=share

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I would:

Check the 200A fuse in the plenum for corrosion. Even if not corroded, remove it and clean the contact points.

Use some long jump leads to connect the battery negative terminal directly to an earthing point on the engine so see if that helps with the voltage drop on cranking.

If it does then inspect the negative cable from the battery and also the earth strap to the engine.

If it doesn't then use the same leads to connect the battery to the 200A fuse to see if that makes a difference. You can try either side of the 200A fuse to eliminate it as a cause.

this contact is already good yesterday monitoring the battery has dropped to 8V 4th start of the day and there has been the 16985 is probably the battery that has died element I will replace and ressayé, I read during the fault the Map is corrupt this leads to battery HS

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Could simply be the starter motor that is pulling too much current on starting and causing the ECU to fault out from low voltage.

also possible he had been redone nine there a few years, I'll test the simplest battery, and you'll keep informed

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Did you make any progress on this?

Had the same error.
Viper Tuning made my ECU back to stock, error caused by bad tune.

With the kindest regards.

Shoppinit wrote: ↑

Wed Jun 15, 2022 3:04 pm

Did you make any progress on this?

yes hello new I'm advancing step by step it's still down but I replaced the battery not a new varta 110AH, same problem after a few starts significant voltage drop +/- 8-9V and error 16985, when cold everything is fine even if not violent when starting hot more difficult, I even replaced the ECU with a second-hand one, reflash the same, check j59 start-up load shedding relay it is good, starter remains faulty when hot (coil, collector, coal ect) or wiring I have to find long cables to test mass and + the 200A fuse

mavada wrote: ↑

Wed Jun 15, 2022 7:21 pm

Had the same error.
Viper Tuning made my ECU back to stock, error caused by bad tune.

With the kindest regards.

mavada,
thank you for the return I am trying in parallel a simple flex map that I had before which worked to eliminate the map, your problem was regular? or like me every 10/15 starts in random ways? I specify that the checksum is made at the injection of map, was made with several external software and inject in boot mode not always the