Hello, my Chevrolet Captiva LS engine won't crank at all as if the battery dead flat. I check the battery with the tester and it's ok. However I notice the airbag warning sign blinks when I switch on the ignition key and it never happens before. Please tell me what is the problem and what to do with it. Thank you.

not told what ,won;t start means, we can;t year it fail. so say the words correct.
the starter motor is dead silent cranking or clicks or chatters only.
of the starter motor cranks the engine fast GRRRRRGRRRRR sound
like it did for 12 years but not now.?
are you DOWN under?

The Captiva is a front-wheel or all-wheel drive SUV; the engines were supplied by Holden in Australia, the Family II naturally aspirated four-cylinder petrol or the Alloytec Holden V6 built in Australia, and later a 2.0-L turbodiesel supplied by VM Motori in South Korea.
my guess is starter motor does work
and the engine is .Familly II diesel

ALL FUSEs tested good
and glow plugs work ( a test) and fuses too.
the pump must pump fuel cranking over the engine
a 2 man test dig>?>?
and must be primed if tank run dry.
12vdc to the pump cranking, using an voltmeter dmm
that is all . (non solder USA,so no books on it)

cranks ok, but will not start
well he low voltage (non told) is from cranking the battery flat/low.
so charge the battery ;.
P0303 codes right? and no others?
power to the fuel pump happens only 3 ways
1: the priming action to pump key on for 1 to 2 seconds, as you can see that is a 2 person job. lacking huge long meter test leadss
2 cranking the pump runs only cranked.
3: engine running.,fully and sustained.
No engine told 3.4L or 3.8L. automatic I resume.
VIN derivative (1) for 3100 LG8 and 3400 LA1
Learn first that injectors are disabled if the pCM sees gross errors with spark, dead cmp , dead ckp or spark feed back dead.
to see that on a scan tool (real)
we use charged battery first.
then scan tool connected we crank for 10 full seconds , no longer.
release the key , not tuned off and see all DTC P03xx not just one.
see them all, and they all matter.
Lacking those events test all spark plugs for spark not just 1.
and test fuel pressure CRANKED a dead engine.
spec is, 3.4L (52-59?psi)

Make sure battery has a full charge. Have a helper crank it while you check for spark at the plugs. If spark everywhere, use a gage and check proper fuel pressure and fuel injector pulse. How long since a tune-up? Any applicable trouble codes?
Chevy doesn't have a fuel cut-off switch. As far as ford--chevy--Chrysler, ford is the only one I know of that has a fuel cut-off switch.

Could you supply a little more info . What is ment by hard to start ? When you turn the key the engine cranks ok but won't start right away ? Or the engine doesn't spin ?

the clicking indicates that the battery is dead or flat. The only test is with a load tester. For a battery to fail quickly especially in cold weather indicates that it was on the way out.

not sure what you said but.
seems the battery is discharging,? 12.6v is fully charged,
own a voltmeter?
try a good loaned battery , does it start the car,?
i think you meant?
i can jumper cable start my car at any time. (off another running car)
but after running my car, the battery discharges and it will not crank at all. right?
this means ,the charging system on your car is bad.
if the starter cranks great, then the engine is flooded or is in great need of a tune up (sparkplugs etc)
if flooded try the super secret in the op guide, crank with throttle wide open , this magic trick cuts all fuel injection allowing the flooding
to purge away, and eventual starting.
my guess 2 is the car wont start, so you crank the battery flat
you jumper start it and it runs. (luck)
then day 2, same deal cranks ok but wont start.. ever tune up the engine?

Chevrolet Aveo 1,6 LS won't start just cranks crank angle sensor ok and coil ok

When you say it won't start do you mean the engine will not turn over with the starter like in a dead battery type of no start, or do you mean the engine cranks over fine but doesn't start? If the latter is the case check the fuel pressure, the test port is on the top of the engine and looks like a tire fill valve, it should be at least 45 PSI while cranking the engine over, you will need to buy a universal fuel injection fuel pressure test gauge from the parts store, about $20.00 should do it.

Check the battery like this:
Turn on the headlights, then try to start the car.
If the headlights do not dim or go out, then the battery is likely ok.
Check that the battery cable plus post, goes to the starter, Minus post to a good ground, like the engine.
If wiring is ok, then look at the starter solenoid for a good connection.
Problem is most likely the Solenoid or starting relay, whichever the car uses.
Hope this helps.

ok heres some thing to check! u need a second person to do this!and a light tester! apply e brakes !locate starter motor ! it will be on the front of the front of the engine! there will be a small wire on it color pink or purple! with the second person in the drivers seat! u must connect the light tester to ground on the car ! as the person turns and hold the key in the start postion u must touch the light tester to the small wire! if u have positive power that the wire ! change the starter!