2004 Chevy Blazer ses light

2004 CHEVROLET BLAZER
76,000 MILES • 6 CYL • 4WD • AUTOMATIC
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KTM513
  • MEMBER
  • 4 POSTS
my blazer shows codespo135 and po155,, I replaced both sensers, cleared codes all ok till the next morn,,again clearsd codes all ok ,,light comes on only when sitting overnight
Dec 16, 2009 at 9:50 AM
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SWILLIAMS
  • ✓ASE Certified Mechanic
  • 597 POSTS
  • ASE Certified Mechanic
Sounds like the power circuit for the O2 heaters has a problem. NOT the sensors themselves. Both of the front sensors get power from the same place, the 20 amp fuse in the under hood fuse box. See if the fuse is OK. If the fuse is OK then pull the connector from either of the sensors and check the pink wire for voltage. If you have a good fuse but no voltage at the sensor check the wiring for damage.

The other side of the heater gets grounded through the ECM.
Dec 18, 2009 at 12:26 AM
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KTM513
  • MEMBER
  • 4 POSTS
I have power to the pink wire,,after taking it to a pro ,,he said to clear the code with a solus?I will let you know if it worked thanks
Jan 1, 2010 at 12:04 PM
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