Oldsmobile/Buick Repair: 2003 LeSabre wont start, daytime running light, air control valve


Question
QUESTION: Cranks but won't start.  I've narrowed it to injectors not actuating.   Has 12 volts, but the noid light shows no grounding. A bad Passkey system can shut off fuel, but the security light does not flash and the dash monitor recognizes "Driver 1."   

My code reader is normal with other cars but acts squirly on the Lesabre.  The trouble code icons keep flashing.  Pin 16 (battery pos.) shows 12 volts; pin 2 (bus pos. line) never stabilizes, but fluctuates from .2 to .7 volts; pin 4 (chassis grnd) shows 6mv; pin 5  (signal grnd) shows 16mv.  Is this an obvious grounding issue, or could a bad ECM cause this?  Or...?

Some other items that might be relevant:
1) Prior to this problem, the battery was draining at night.  I traced it to the power seat with an amp test and removed fuse;
2) idle air control valve continuously clicks with the key "On";
3) With the key "On," running lights can't be shut off. Removed "Daytime Running Light" fuse and relay, but lights stayed on.

ANSWER: HI JOHN, REMOVE THE IGN MODULE AND SAND THE BASE DOWN REAL GOOD AND CLEAN..ALSO THERE IS A SMALL GROUND WIRE UNDER THE MODULE PLATFORM,CLEAN THAT AS WELL.VERY COMMON PROBLEM.. LET ME KNOW WHAT HAPPENS..THIS MAY HAVE A BAD BCM [BODY CONTROL MODULE]WITH THE LIGHT ISSUES.. WILL GET INTO THE OTHER PROBLEMS LATER. LETS GET THIS GOING FIRST. RUNNING LIGHT PROBLEM SOUNDS LIKE A SHORT FROM THE LIGHT MODULE TO THE SWITCH..GET BACK TO ME AFTER YOU CHECKED THE ABOVE OUT.TOM.

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QUESTION: Hi Tom.  I did as you asked.  The idle air control valve no longer clicks continuously.  The other symptoms are the same.

Two other symptoms I neglected to mention earlier:
1) the Check Engine light does not come on with the key "On";
2) a few days before I found out the battery drain problem and removed the fuse to the power seats, I used a trickle charge overnight.  The next morning the starter would not crank, until I jumped it to the solenoid.  Since then the starter cranks with the key.

One other thing I did was to test volts at the ICM plug in.  The P circuit wire (power) shows 12 volts, the K circuit wire (ground) shows good ground, the N circuit wire (IGN) shows 11 volts (range of 10-12 volts okay).

Also, there is 5 volts in the 5 volt system, based on a test on the gray wire at the TPS.

ANSWER: HI JOHN, THE 5 VOLT REFERENCE SIGNAL TO THE TPS TELLS US THAT AT LEAST ONE SIDE OF THE PCM IS OK,THIS IS GOOD....THE OTHER VOLTAGES ARE OK.. THE CK ENG LIGHT NOT COMING ON BOTHERS ME..HAVE YOU CHECKED ALL THE FUSES FOR THE CK ENG LIGHT NOT COMING ON ???? IF NOT PLEASE DO SO.CK THE CIGAR LIGHTER FUSE I THINK THIS IS THE FUSE FOR THIS CAR.. WOULD ALSO LIKE TO KNOW IF THERE IS A CRANK SIGNAL WHEN THE ENG CRANKS ??? YOU DO HAVE A SCAN TOOL WITH DATA CORRECT ??? THE STARTER NOT WORKING ALSO BOTHERS ME,THIS MAYBE A FLUKE THING OR BAD STARTER COMING ON OR THE BCM IS SHUTTING DOWN AT TIMES, WHICH I AM WONDERING IF THIS IS SOME OF YOU LIGHTING PROBLEMS AS WELL.
CAN YOU CK FOR FUEL TO THE FUEL RAIL CK VALVE. IF YOU HAVE FUEL WHILE THE ENG IS CRANKING OVER AND[MAKE SURE FUEL IS THERE WHEN CRANKING ENG OVER THE ENTIRE TIME] A 5 VOLT REF AT THE TPS AND CRANK SIGNAL THIS SOUNDS LIKE A BAD IGN CONTROL MODULE..THIS WILL SHUT DOWN THE INJ SO NO PULSE WILL BE FOUND...YOU ALSO SAID ON YOU FIRST QUESTION THAT THE CK ENG LIGHT WAS FLASHING ? NOW IT IS NOT ON AT ALL ?? I HOPE THIS IS JUST A FUSE AND NOT THE PCM. AS FAR AS THE DRAW FROM THE POWER SEAT THAT COULD BE JUST THAT. MOTOR SHORTED OUT MAYBE..LET MEW KONW HOW THIS GOES GOOD LUCK TO YOU,,,TOM...

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QUESTION: Hi Tom.  I checked all the fuses and they are good.  Fuses with 12 volts on one side, show 12 volts on both sides.  Fuel pressure is good at the Schroeder valve through the crank cycle.  The check engine light doesn't flash, rather it does not come on at all.  I don't have a scan tool with data correct.  I've read how to test crank signal with an LED light.  Do you want me to try this?

Another weird thing...  After I tested each fuse for voltage, I ran a second test, but a different way.  The second time I tested the fuses I probed one side with black, the other with red.  When I got to fuse 10, left side high beam, the left headlamp came on.  Sometime during this month-long episode, that headlamp would not come on.  But after this second fuse test, it now comes on.  As well, all running lights now shut off on their own when I turn the key to off.  I did not mention these particular problems before (one headlamp not coming on, and the running lights not shutting off when the key is off) because I did not want to confuse the issue.

Answer
HI JOHN, WOW,LETS TALK ABOUT THE TESTING FUSES BOTH WAYS,I AM NOT FOLLOWING RED AND BLACK,POWER AND GROUND [YES.IF THIS IS THE CASE, SELF POWERED TEST LIGHT ??YOU FED POWER BACK THROUGH THE SYSTEM AND YOU SAY NOW THE LIGHT WORKS AND RUNNING LIGHTS NOW SHUT OFF. THIS WOULD GO RIGHT TO THE BCM THROUGH THE RELAY....WE KEEP GOING BACK TO THE BCM..INTERESTING. AS FAR AS YOU TESTING FOR A CRANK SIGNAL WITH A LED THAT IS OK..SEE IF YOU HAVE A SIGNAL THERE. I SUSPECT MODULE,BUT I DO NOT LIKE THAT THE CK ENG LIGHT DOES NOT COME ON. I WONDER IF THE BULB IS BAD !!!IF THIS WERE THE CASE I WOULD FEEL BETTER ABOUT THINGS.. YOU COULD CK FOR POWER FEED WIRE FROM PCM FOR 12 VOLTS [YOU WOULD NEED A WIRING DIAGRAM FOR THIS]  OR PULL THE DASH FACE AND CK THE BULB..THIS IS WHY I WOULD REALLY BE MORE HAPPIER IF YOU COULD GET THIS SCANNED FOR DATA. WE HAVE FOUND MANY TIMES THAT CERTAIN SECTIONS OF THE PCM FAIL AND OTHER PRINTED CIRCUITS ARE WORKING AS THEY SHOULD BE. THIS THROWS MANY PEOPLE A CURVE. I WOULD NOT BE HAPPY IF YOU WENT OUT AND BOUGHT A NEW ICM AND THIS IS NOT THE PROBLEM. YOU WOULD NOT BE HAPPY EITHER..THIS IS WHY A DATA SCAN WOULD BE SO IMPORTANT FOR THIS CAR,YOU COULD CK THE BCM AND SEE WHAT IS OR NOT WORKING,YOU COULD ALSO SCAN THE PCM AND TELL IT TO TURN CERTAIN THINGS ON AND OFF AS WELL AS THROUGH THE PCM,IF NO SIGNAL IS SENT THEN THE PCM HAS FAILED. YOU SEE WITH A SCAN TOOL YOU CAN DEMAND THINGS ON AND OFF...I KNOW YOU WOULD LIKE TO FIX THIS WITHOUT GOING TO A SHOP BUT GUESSING HERE COULD GET VERY EXPENSIVE..BUT I WILL WORK WITH YOU THROUGH THIS ANY WAY YOU WANT TO...FEELS LIKE I KNOW YOU,,,TOM