Thursday, April 14, 2011

Erratic operation of ‘Water in fuel filter’ light usually indicates failing battery in Swift (diesel)

A couple of months ago, ‘Water in fuel filter’ light came on (along with SVS light) in my Swift Vdi. I drained the fuel filter but the light kept coming on (and often going off during the next start-stop cycle, only to come on again after a day or two). In other words, this warning light started behaving in an erratic manner and its coming on and going off had nothing to do with presence or absence of water in the fuel filter.

As expected, even on days when the ‘Water in fuel filter’ light did not come on, the SVS light did not go off after 4 seconds of turning on the ignition. This happens because when the ECU detects a fault, the fault code (DTC) is registered in the ECU and the SVS light won’t go off after 4 secs of turning on the ignition unless the DTC code is ‘cancelled’ using the Tech-2 diagnostic tool.

I took the car to MASS where they found the DTC code to be P2264 – ‘Fuel filter water detection sensor circuit’. Since it was already established that the warning light was behaving erratically, the MASS suspected the battery because they had come across many cases of warning light malfunction when battery was weak in diesel Swifts.

Even in this forum diesel Swift owners have reported malfunction of warning lights with a weak battery. Therefore, I decided to thoroughly examine my battery (original Exide DIN 65 MF) before taking the decision to change it. I must mention here that I started experiencing some minor starting problem at this time.

I removed the battery from the car and charged it overnight with my external battery charger. The specific gravity readings were as follows :
Initial sp. gr. 1250 1250 1250 1250 1240 1250
After charging 1280 1270 1280 1270 1260 1280

After overnight charging, all cells were gassing freely, i.e., battery was fully charged. Terminal voltage was 12.85V.

From the specific gravity readings it seemed to me that the battery was okay and I fitted it back in the car. Things worked fine for a few days and thereafter the ‘water in fuel filter’ light started coming on again. Also starting problems increased greatly. On a couple of occasions when the car refused to start after 2-3 attempts, I feared that the car may not start at all, but luckily the car started on the 3rd or 4th attempt. One thing was sure -- something had to be done urgently to prevent getting stranded on the road.

I then got the battery load tested at a battery dealer and when it failed the test, the decision to buy a new battery was obvious.

After substantial research on the internet I decided to go for Base Terminal DIN 66 BT MF. I found that Base Terminal had built a reasonably good reputation in the Indian market, offered 2-year replacement warranty followed by a 2-year pro-rata discount warranty and good value-for-money. I bought this battery (from M/s Moonka Sales, Q-Road, Bistupur, Jamshedpur) for Rs 6800 and received Rs 800 as buy-back for my old Exide – in other words, I had to shell out Rs 6000 only.

After fitting the new battery, I got DTC cancelled at MASS. All problems resolved thereafter.

To summarise :

1) Specific gravity of all cells in a lead-acid battery may be okay but only a load-test can reveal the actual health of the battery. The battery should be able to deliver enough current under full load (during starting) to crank the engine at a high enough RPM to successfully start the engine. This is especially relevant to diesel engines because they have a high compression ratio and the temperature of the compressed air at the end of the compression stroke holds the key to ignition. In other words, it is not enough that the battery is able to crank the engine – the battery should be able to crank the engine at a sufficiently high RPM to initiate ignition of the fuel injected towards the end of the compression stroke.

2) In the 1.3 lit Multijet engine (fitted in diesel Swift and some other Indian cars), the ECU and Sensors seem to be quite sensitive to the battery voltage and tend to malfunction when the battery becomes weak (voltage falls). Erratic and false operation of warning lights, usually the ‘Water in fuel filter’ light, appears to indicate a failing battery.

3) The battery life in a diesel car seems to be significantly less than in a petrol car with comparable BHP. This is mainly due to the fact that a battery is subjected to much more stress every time it starts a diesel engine because diesel engines have a high compression ratio and much more force is required to crank a diesel engine. Furthermore, a petrol engine can start at a lower cranking RPM as compared to a diesel engine and therefore, a battery which is incapable of starting a diesel engine can continue to start an equivalent petrol engine for some more months.

4) The original Exide battery in my Swift Vdi lasted for about 3 ½ years (with no shortcoming in maintenance). Batteries in my earlier petrol cars (Maruti-800, Premier 118NE and Maruti Esteem) used to last for 4 to 5 years.

5) It is perfectly safe to disconnect (or take out) your battery in a diesel Swift for a day or more because the non-volatile memory in the ECU ensures that all essential programming and data for efficient operation of the engine, odometer reading, etc., are retained. Every time you disconnect your battery, you only lose your music system and trip meter settings.

6) Base Terminal seems to be a good value-for-money option to Exide and other leading battery brands in India. However, I would like to give my final verdict only when this new battery dies (if I’m still married to my Swift Vdi then!).


shweta said...

Thanks for sharing this maruti swift's information through your cars blog post.It was very helpful to me as i had been searching for it on the internet.Thanks a lot for this information sharing.

Rajesh Shrotri said...

Thanks a lot for this info. Nowdays I am also facing the same problem. I will certainly follow your ideas.
Rajesh Shrotri

Godwin said...

Thank you sir for the valuable information. Coincidentally, about a week back my Swift VDI too had the "water in fuel filter" light and the SVC light on. My car is about close to 4 years and starting the car takes a bit longer nowadays. I safely assume the battery to be going bad. I understand by default for Swift VDI any DIN65 battery is recommended. But I have seen a few of my friends having a DIN74 battery installed which is slightly expensive. Is there any advantage using a DIN74 over a DIN65/66 battery?

Debashis Mukherjee said...

Dear Godwin,

A DIN74 battery has higher capacity (ampere-hours) as compared to DIN65. But I see no significant practical advantage in fitting a battery of higher capacity than what is recommended by the car manufacturer.

J Gos said...

Very good and informative post.

However I see that your posting frequency has decreased significantly !

Please post more regularly of your VDI experience. I look forward to it.

Debashis Mukherjee said...

Dear J Gos,

My posts have probably reduced because my Swift Vdi is giving me a totally trouble-free service. So there is nothing new to talk about!

Raajan said...

Thnx fr ur post, as it was quite helpful fr me 2...
My swift vdi is just 2 years three months old and it is giving me the same problem...
Now i realised that switching off the engine is not enough while sitting in d car and the fan/AC is on... Perhaps that only has eaten my battery so soon.
And now i am sulking...
I got my battery checkd frm a local dealer and he said tht one cell is weak in d battery. I also got stuck in traffic jam twice as d car cdnt start..
now i m buying SFSonic DIN74 battery for Rs 7500 in replacement of my DIN65.. Please suggest, is it fyn? I based in Delhi.. Eagerly waiting fr ur reply..

Debashis Mukherjee said...

Dear Raajan,

I'm not very sure about the quality of SF Sonic battery -- especially for diesel cars. Please double check from MASS before buying it.

Alternatively, you can buy Base Terminal DIN 66 BTMF battery -- I am using it in my car without any problems.

lohith said...

Thanks for sharing this encountering this same problem,i ll surely follow ur suggestions.Tnk u once again.

Chandan said...

Dear Mr. Mukherjee ,
I am facing this exact problem since three weeks , my car a swift vdi was bought in feb 2010 and has done 32000 kms .
i was just wondering as to what would explain battery failure so early ??

Chandan Chawla

Chandan said...

Dear Mr Mukherjee,
I was also wanting to know as to what is battery life dependent on ??
number of kms or months/year since purchase ??

Chandan Chawla

Debashis Mukherjee said...

Dear Chandan,

The life of a battery depends on many factors. However, since battery manufacturers offer time-based (and not kilometre-based) warranties, it is safe to assume that a car battery is expected to last a certain number of years under normal usage and maintenance, regardless of the kilometres.

Your car is just one and a half years old and it is too short a time for your OEM battery to fail. Please get your entire electrical system checked by MASS and if your battery is indeed failing, do insist on your entitlements under warranty.

Bobin said...

thanks for sharing your experience

i also had the same problem and the dealer mechanic told me the same reason which u shared. i had this problem in 2 years 20 days after my car purchase.. and 50k kms ;

please let me know about the warranty after 2 years ; directly from exide is there ????

Mohit said...

Hello Sir,

Can you suggest me a good battery for Swift D'zire Diesel?

The OEM Battery(Exide) only lasted 2.5 yrs/23.5k+ kms so it was a big let down.

I checked out BASE's website but they do not have one listed for Swift D'zire Diesel. For Swift Diesel they have 2 models on display:

So can we use the above batteries(for swift diesel) in D'zire diesel also?


Debashis Mukherjee said...

Hi Mohit,

The engines of Swift and Dzire are the same. So batteries suitable for Swift (diesel) are equally suitable for Dzire (diesel).

vicky said...

very nice information , is it safe to go for a long trip if the light is on

Debashis Mukherjee said...

Dear Vicky,

I would not advise anybody to go for a long drive on Indian highways with any ECU error.

Shire Consulting said...

Thanks for sharing this maruti swift's information.

Suzuki Engines

dr. ramakrishnan said...

Dear DM,
I've been facing exactly the same problems in my 2009 swift VDI and luckily I saw your blog in google. How is your base terminal doing and what's your opinion on amaron? Amaron have a 3 year and a 5 year warranty types. Which one would you suggest?

Debashis Mukherjee said...

Dear Dr. Ramakrishnan,

My Base Terminal battery is only 10 months old and it is too early to comment on its long term performance. It has been working perfectly so far.

I have never used Amaron batteries and therefore unable to comment. Choosing between a 3-yr and a 5-yr warranty would depend on :

1) How long you intend using your car before replacing it

2) Cost-benefit analysis

carazoo said...

It’s in reality a nice and useful piece of information. I’m glad that you just shared this helpful info with us. Please stay us up to date like this. for more info about maruti swift

Mahendran said...

Thanks for the valuable information! My swift LDi is just 2 yrs and 2 months old and started giving same trouble with the Battery, i.e. with the same wet fliter and SVS indications. Today I checked the battery and the test concluded that it has to be replaced. I am yet to decide on the brand... will do it in a day or to.

I wonder if there a best practices to last the battery life for longer duration?

Debashis Mukherjee said...

Dear Mahendran,

To maximise battery life :

1) Ensure that electrolyte level NEVER falls below the top of plates.

2) Always use good quality distilled water to top up electrolyte. NEVER use acid.

3) Do not unnecessarily drain the battery, such as by keeping headlights on with engine stopped.

4) Don't allow the battery to get fully discharged.

5) Any defect in the charging system should be promptly rectified.

Mahendran said...

Dear Debashis,

Thanks for the tips and I appreciate your prompt response! I'll try to follow it.

There were couple of instances where I stopped the engine & switched-on the blower for about 5 to 15 mins. The mechanic also advised not to use blower when the engine is stopped.

One question: Typically, how frequently we have to top-up the electrolyte to keep-up the level? Once in a month?

Debashis Mukherjee said...

Dear Mahendran,

Using the blower once in a while for 5-10 minutes with the engine switched off should not cause any problem. It is the headlights that drain the battery more quickly.

Modern lead-acid automotive batteries usually require very little maintenance. Checking electrolyte level every 5000 km or 3 months should suffice.

Mahendran said...

I've changed my car battery on 6th April with Exide Matrix type. It costed me Rs.8800 (New Batt:9500 - old Batt:700). They claim that its a maintenance free battery with 30 months replacement warranty + 30 months pro-rata based warranty.

I could have got some better deal, but my car didn't give me a chance. On Friday evening I went to Amaron shop for enquiry, but he didn't have stock. So I went to a near by Exide shop, just checked the price as I didn't have any plan to change it immediately. When I started the car, it didn't start :-( I tried for about 15 mins, but no use. It was already 9pm and the shop was about to close. So I decided to purchase there itself, closed the deal and replaced there itself.

Its good that the car didn't start in front of the Exide shop, because I had planned a long drive for that weekend (about 1000 kms, Chennai to Vijayawada).

Srinivas said...

Thanks a lot for posting this.
It was very useful and with all the required details for this issue.
I own a Swift VDI of 3 and 1/2 year old. From recent past I am facing the same issue and when I visited MASS, it is nothing to do with engine or some other part. The Battery is weak and due to which the 2 light are started glowing. But when they check the battery condition, it says GOOD.

Lately I have noticed it is taking few seconds more to start the engine. I think better I go for a replacement of the battery.

Amitava Chakraborty said...


prabhjot singh said...

Thanks for your precious information. i have swift vdi 2010, i am facing the same problem since last week. It takes too much time to start. i bought new exide battery 2 years ago. should i change the battery or you have any substitute. And how to check that i should change the battery. pls help.

Debashis Mukherjee said...

Dear Prabhjot Singh, Please get your battery checked by an Exide dealer. They will be able to ascertain the actual condition of the battery by carrying out a load test.

anny said...

Dear DM, In my swift ldi,wrench comes on while running ,I have taken to MASS,already 4 times ,I went to mass,today same problem came,they cleaned,fuel tank,egr valve,fuel filter in 3 times,surprise is no code showing while connecting sdt

Debashis Mukherjee said...

Dear Anny,

I am unable to diagnose the problem.

Mukesh Upreti said...

Hi Debashis
I have an April 2014 Swift VDI with the same issue that cropped up today when i started the car. the water in fuel tank indicator comes up on and off. what do u suggest? battery replacement?