Swift DDIS SVS Light turns Off only after engine starts(ECU records immobilizer code)

Hello Mods, Friends and Experts, Greetings to all! :) I have a query regarding an issue that my car has been experiencing. Its a Swift DDIS(ABS). It has completed three years this month. Its a well maintained car with engine oil and oil filter changed at every 5000Km and serviced at regular intervals. The ODO is about to cross 29000km. The issue started 2 months back. It was in the mid rainy afternoon and the car had started with no issues at the first attempt. A 4 km drive. Parked the car. Had lunch at a restaurant. Headed towards the destination back in my car to another 4-5 kms with friends. We finished our work in about 30 mins. Headed towards the car. Turned on the ignition waited for the SVS light to turn off and then attempted to crank the engine. It started up and it turned off immediately with the SVS light blinking continuously. I turned off the ignition waited for 5 seconds. Tried cranking the engine and it wont start. Again turned off the ignition waited for say around 10 seconds, attempted to crank the engine and it started up just fine. I noticed that prior to the engine start, as normally I do, I wait for the SVS light to turn off itself, but now it didnt, and would turn off only when the engine starts up. Went to MASS, got their SDT connected and checked the error code. It said "P1612 & P1613 - Immobilizer Malf". They cleared the error, and suggested me to continue using the car, as this might be a one off, however it happened just again in a weeks time, exactly the same behavior albeit the engine started up at the second attempt. The error code registered was the same. They cleared the bit and advised me to use my second key as they suspected key electronics to be the culprit. All went fine for almost close to 2 months, and one fine morning around 15-20 days back at the first attempt of the day to crank my engine, it again gave the same issue, but the engine started at the second attempt. (Please make a note, I am using the second spare key as suggested by MASS advisor) Checked again with MASS, and its the same error code. We are able to see this code when we click the History option of SDT. They say, it saves it to history from current, hence it comes up under history section of SDT when the issue has occurred and recorded by the ECU. The issue has occurred thrice in these 15-20 days and another service advisor is pointing to a weak battery even though the error code mentions something different as above. However I am not convinced, because the engine starts and then dies immediately as if someone has turned off via the key. And the car even starts up with no signs of a too weak battery before or after this issue has occurred. They have asked me to leave the car with them for 2 days starting today. I am not comfortable keeping the car that long, but have no option although they have been co-operating so far as they should. I have asked them to check with their service battery which they say they don't have and would try to arrange one. I doubt in two days they would get the same issue, as it sometimes just works fine for more then a day/week/month. If they nail down to a weak battery, they should let me check it with service battery for at-least a month considering the behavior of this issue. DDIS battery is too costly compared to petrol version swift. The reason I have not yet bought a new battery is "what if the issue remains even after the battery change" as the error code talks something else. I would then have already dented my pocket with 10k for a new battery for no fault of it. Has anyone in our forum ever experienced similar issue with their Swift DDIS where the problem identified was a weak battery as against what the error code talks and that being the final resolution. Please pour in your thoughts and experience, as it would help me understand and drive this issue to a good resolution without damaging anything in my car. @anshurao, I read your similar issue in Jaggu's thread but I didn't pay attention if the water filter light too had come up in my cars case. And again, you have not mentioned the error code. Was it the same error code that your car ECU reported ? @Mods, I didn't find a dedicated thread for SVS light issue, nor do I want to hijack anyone elses thread which apparently is ownership review, hence started one. Please move it as suitable if not appropriate. Thanks in advance. tush.

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