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1999 S70NA Evita ECM-720A (P0630 P0645 pend)

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

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1997 - 2004 C70

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1999 S70NA Evita ECM-720A (P0630 P0645 pend)

Post by abscate » Fri Apr 26, 2019 8:28 am

I had trouble getting keys made for Evita, so I did the tape the key to the Immob ring under dash, and have three keys cut and unshipped to run car.

The starting has always been a bit strange
First crank starts and then does the immob stall 2 seconds later.
Wait three seconds, cranks and starts fine.

I managed to get some understanding on this today.

I detected ECM-720A IMMOB fault, and when I cleared it, the car starts first time. Reading the webs, it seems like leaving the key in too long will pop a ECM-720A, but no CEL, (a P0630 or P0645 pends but I don't see those)

The next question is, How long is too long for the Key?

I could rig up the ring with a relay that closes on Term 15 to stop this of course.

:D :D :D



This diagnostic trouble code (DTC) indicates that the configuration between the engine control module (ECM) and the immobilizer does not correspond.
The immobilizer transmits the VIN code to the engine control module (ECM) at start attempt. Diagnostic trouble code (DTC) ECM-720A is stored in the engine control module (ECM) if the engine control module (ECM) interprets the code as faulty or missing. The engine control module (ECM) will not allow the engine to be started.


Possible source

Faulty signal:
an engine control module (ECM) that does not correspond to the immobilizer code has been installed
an immobilizer that does not correspond to the engine control module (ECM) code has been installed
defective immobilizer
defective engine control module (ECM)
open-circuit in the communication between the immobilizer and engine control module (ECM).
engine does not start

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1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW