SRS light / low crank voltage

[braves6117]

Just starting happening with the last 6 start ups. SRS light comes on, goes away 1 -2 minutes later, so I'm assuming its low crank voltage. So, before I begin trying to resolve the matter, I wanted some advice.

Is this an indication that the alternator is on its way out?

Battery is nearly 2 years old, and is the Odyssey pc2150 "big boy."

Found a way to test the alternator here:

http://discoweb.org/forums/showthread.php?t=59227&highlight=alternator+testing

I'll go ahead and get that done and report back.

Most searches reveal info on airbags and seat belt tensioners related to the SRS.

Anyone with a similar experience like mine?

Thanks for all the help guys.

 

[Jagfixer]

Use a volt meter and check voltage of battery without the vehicle running. Start vehicle and see how much more voltage you get. Example: 12.75v when battery alone, 14.25v with motor running ( altenator OK). Then do a load check on battery to see if it holds the 12v while cranking.

 

[braves6117]

Ok, thanks Jag.

Battery voltage with vehicle off: 12.49v

Battery voltage with vehicle on @ idle: 13.89v

Battery voltage with vehicle on, A/C on, and rear defroster on: 13.84v


Guess this suggests normal operation of the alternator?

Also, the SRS light either comes on just after start, or about 10 seconds after idle begins, if that matters...

Where should I look next? Seat belt tensioners huh ?

 

[justintoxicated1]

I get that same SRS problem. It will come on. Sometimes go off and stay off for quite some time, then come on out of the blue. Finally had the code read, Passenger pre-tensioner open circuit, driver side Airbag open circuit. I unlplugged and plugged back in both. Still get the SRS light. Hope you have better luck!

 

[ptschram]

If the SRS light goes out, don't sweat it. If it comes on and stays on, then worry.

Be aware that some diag computers indicate open circuit, driver's side. This is usually the connector beneath the seat, NOT the steering wheel airbag.

 

[justintoxicated1]

eh, mine stays on all the time now. I bought a new battery a while back because I thought I had low voltage for the SRS light to be on, plus I needed a new battery anyway. Unplugged the pretensioners on both sides then plugged them back in. No dice, light still on. Thanks for the input on the diagnostic computer, PT.

 

[ptschram]

If a fault was logged for "low battery voltage during cranking" you will need to have a Rover computer to reset the SRS.

On the DIs, it was very common for this fault to become fatal to the SRS ECU.

 

[justintoxicated1]

Stupid question, you unplug the pretensioners when the vehicle is off? I still have open circuits on both passenger and driver sides after unplugging and plugging in. This issue has been plaguing me now since May.

 

[dmarchand]

Won't go away unless you replace the pre-tensioner. I just had this happen on my '04. Tried unplugging, etc. Dialectic grease, no luck. Replaced and all is well with the world. Maybe WillT has some in stock.

 

[ptschram]

Won't go away unless you replace the pre-tensioner. I just had this happen on my '04. Tried unplugging, etc. Dialectic grease, no luck. Replaced and all is well with the world. Maybe WillT has some in stock.

I'm about 50% with disconnecting, cleaning and painting with this stupidly expensive conductivity enhancer goo-that I've run out It's worth a try!

 

[ptschram]

Stupid question, you unplug the pretensioners when the vehicle is off? I still have open circuits on both passenger and driver sides after unplugging and plugging in. This issue has been plaguing me now since May.

YES! Don't fawk with the SRS system when it's hot! I've become pretty contemptuous of them, but I know it's only a matter of time.

 

[justintoxicated1]

heh, i started the rover up, SRS light lit up like normal, then went off like nothing's wrong. I love how this keeps happening. oh yeah, and i didnt mess with anything.

 

[The Fourth Amigo]

I had similar problems and thought the alternator was on the way out. I was cleaning the ground connections when I noticed the engine ground to chassis was broken and the whole thing was grounding through the hand brake cable. I replaced the ground cable with a piece of 1/0 welding cable and everything was OK.

 

[monkeyboy]

On the DIs, it was very common for this fault to become fatal to the SRS ECU.

So is it bad that mine's been on for the past eight years or so?



KAA