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jbrasch 11-07-2013 06:56 PM

2005 l300 occasionally does not start
I have a L300, 2005, with 106,000 miles....lately it has been having a difficult time starting. It turns over, but does not start. New battery, connection good, changed spark plugs, new timing belt...mechanic thinks it is the BCM.
diagnosis code P1632 when car was not starting. code in BCM B0936, B2958, B1327, B3109, B2575, B2585. Getting tired of spending money.....

Any suggestions/thoughts would be appreciated.
Thank you,

fdryer 11-07-2013 08:20 PM

Re: 2005 l300 occasionally does not start
Is security flashing while starting? Security must be OFF while starting. A flashing security indicator during starting means GM's Passlock disabled injector operation as a theft deterrent. Security OFF while starting means an EFI system problem, not bcm. Passlock is part of many functions the bcm has.

Two things to check, fuel and spark. Air is assumed being ingested while starting to make the recipe work - a running engine. You may have to check fuses.

Fuel is the easiest to test for since a fuel test valve is within reach on top of the engine, "T" fitted onto the stainless lines. Turn on ignition, listen for the faint hum/hiss sounds of the fuel pump running for 2 seconds. Locate the fuel test valve covered with a large black plastic cap, remove cap to reveal the schrader valve, cover loosely with a rag while depressing the valve stem expecting a fuel spray. Cycling the fuel pump can only work if you wait at least 15 seconds with ignition OFF before trying again. A built in timer prevents cycling the pump excessively. (on the other hand, the pump is running when the engine's running) There's a fuel pump and injector fuse. If fuel sprays out then fuel and pressure are available to the injectors. Power to the injectors are a separate fuse. Spark is next.

Spark is the entire ignition system operating correctly and most difficult to test because of inaccessibility to plugs without plug wires. A different approach is needed to test for spark for L300's, indirectly. The indirect test actually tests for an intermittent or failed crank position sensor (CPS). A spark test on other Saturns with plugs and plug wires is easy to perform but not our L300's. A leap of faith is needed to test for a failed cps requiring removal - its next to the oil filter canister, mounted with one bolt. A resistance measurement with a multimeter should display 700-1200 ohms at room temperature, after immersing in boiling water or when rapped a few times against a table; heat,cold, and vibration are the environment cps' operate in. Any reading other than specified means a faulty crank sensor.

The cps supplies precise timing signals that the ecm needs in order to operate; the fuel pump, ignition system for spark, and pulse injectors. No cps output = no pump (while starting), no spark, and no injector pulses, a dead engine. With L300's, you can burn out the starter and battery but the engine will never fire up with a faulty cps.

fdryer 11-07-2013 09:03 PM

Re: 2005 l300 occasionally does not start
P1632 doesn't seem to be a valid error code. What does it point to? All other B-codes point to the bcm. Usually, bcm issues are announced with all the bells and whistles randomly turning on and off, instrument gauges/lights flashing, etc.. Posts by members described this as a car that's possessed. Worse case failure of the bcm - security is enabled permanently, disabling the engine from running, requiring a tow to GM to replace the bcm. Used bcm's can be 'married' to the car with a 30 minute relearn procedure posted here several times, retain mileage and cannot be altered. Remotes have to be programmed by GM.

s3nfo 11-08-2013 10:11 AM

Re: 2005 l300 occasionally does not start
P1632 from my Auterra Scantool GM specific code library "Theft Deterrent Fuel Disable Signal Received". You might try the Passlock Relearn proceedure and see if that fixes it. With the theft deterent code and all the B codes, your mechanic may be on to something.

fdryer 11-08-2013 12:26 PM

Re: 2005 l300 occasionally does not start
^ Good info. ^

If the security indicator is flashing during starting then Passlock is enabled and actively disabled the injectors to prevent the engine from running. The starter will crank the engine but no injector pulses just means the theft deterrent system is enabled. Either a 10 minute wait with ignition ON will reset Passlock for another restart attempt or the 30 minute Passlock relearn procedure is needed. For the 10 minute reset, leave ignition ON until security stops flashing, cycle the ignition switch OFF and try starting again - security should be OFF during starting.

toledo589ad 04-17-2021 12:03 PM

Re: 2005 l300 occasionally does not start
Hey there, 2001 L200 with the same occasional fit of possession. Not sure what sets it off but I noticed it happens when it warms outside, above 50F. Sometimes it can take days for the thing to start again. The relearn procedure gets it to start but door locks, dash lights, interval wipers, dash lights, trunk release still do not work. Now that we have shared our adventures, does anyone know what the fix is? I inspected the BCM visually and cannot find any cracks on the board or loose connections that could be aggravated by heat. Thinking of sending the BCM to be remanufactured by Module Experts in Florida. That way it will still be the same BCM coded to my Saturn's VIN. I have no idea if I could get a used one and if it can be reprogramed and how much it would be. Thanks

fdryer 04-17-2021 01:56 PM

Re: 2005 l300 occasionally does not start
toledo589ad, you may have more than one problem.

*Is Passlock security off during starting? If it's flashing, factory security disables injector operation. If it's off during starting, factory security isn't preventing startup.

*Descriptions seem to point to the bcm. It has Passlock programming, runs the instrument panel gauges and indicators except airbag and abs, and runs interior and exterior lighting. It also passes error codes from all modules to the obd port. No one has proven third party electronic repair shops capable of repairing or programming bcm, ecm, pcm, airbag and abs modules. GM service manuals simply state if a module is faulty, replace it with a new one programmed from GMs Tech II scantool. You can search within these forums and determine for yourself members using third party repair shops in electronics. Rarely has any member provided positive feedback after so called repairs were made. Maybe the shop you're interested in has equipment and experienced techs, or not.

Perhaps starting a new thread won't distract anyone from reading the title and be misled with your 2.2L problems different from L300s.

Bcm failure occurs with most here using a used from a junk yard. Mileage remains permanent to used BCMs despite some claiming their used BCMs had their mileage changed. Anti tampering laws prohibit altering mileage. Only new blank BCMs are programmed with mileage recorded from the original as shown on the odometer. Most here are fine with discrepancies in mileage and only have to ensure their state motor vehicle department are informed when state inspection occurs. Remotes have to be programmed to the replacement bcm with GMs scantool or an aftermarket clone. I don't know if used BCMs allow altering the VIN ID.

Rj 2000 LS2 04-18-2021 02:03 PM

Re: 2005 l300 occasionally does not start
We experience the exact same possession. What we know and identify is if the security light is blinking we have to turn the Key to the ON position and sit for 10 minutes and it will turn off and then the car will start.

This normally only happens when I get into the drivers seat. If I crank on the steering wheel while getting in the drivers seat, the security light will go ON every time. Some how some way the Saturn believes I am a thief and it security locks me out. Not an issue in the summer, but in the Winter it's a real pain in the rss!

There is a work around, but since I learned how to gingerly get into the drivers seat, it isn't a common occurrence. The work around is to get at the wiring inside by the key switch, disconnect the Orange wire and add a resistor to ground. This advice might not be correct, but it is on YT. The key is a resistor and the resistance is measured for security. If the resistance is not what it had been learned to be, the security light fires and the engine will not start. We sometimes have trouble with the key fitting and inserting without moving the steering wheel a bit... and I suspect this plays a role in setting off the security phantom too!

You've spent enough money! Time to get exorcise the demons!

PS if the security lock is not the problem, I would replace the Crank Position Sensor (CPS) It is cheap and easy to replace. Sometimes these are intermittent. I had one that died while idling for a few weeks before it stopped working altogether and then the engine wouldn't start.

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