2009 Chevrolet Silverado – Poor Heat If Temperature Set Below 90°F

This 2009 Chevrolet Silverado came in with the complaint that the heater was only mildly hot unless the temperature was set to 90°F. When set to 90° the heat worked very well. I should point out that this truck has automatic HVAC controls as evidenced by the word “Auto” on the control head assembly. I … Continue reading “2009 Chevrolet Silverado – Poor Heat If Temperature Set Below 90°F”

2009 Chevrolet Silverado Driver’s Side Air Stuck On Heat

This 2009 Chevrolet Silverado came in with the complaint that the a/c was blowing out hot air on the driver’s side of the dash.The vent temperature was 140°F and the outside air temperature was 97°F in August in sunny South Carolina. I told the customer that I would not be able to get to it … Continue reading “2009 Chevrolet Silverado Driver’s Side Air Stuck On Heat”

2004 Cadillac CTS Ignition Will Not Turn Off Completely

This 2004 Cadillac CTS came in with the complaint that the ignition switch would not fully turn off. The engine started and ran normally and could be turned off but the key would stop rotating as if the shifter was still in gear. As a result the battery would go dead. First things first if … Continue reading “2004 Cadillac CTS Ignition Will Not Turn Off Completely”

2008 Chevrolet Avalanche Right Front Turn Signal Inop

This 2008 Chevrolet Avalanche came in with the complaint that the right front turn signal did not work. This article applies to Avalanche, Escalade, Silverado, Sierra, Suburban, Tahoe and Yukon trucks and suv’s.  This generation of GM truck or Suv does not use a turn signal flasher relay as we have always known in the … Continue reading “2008 Chevrolet Avalanche Right Front Turn Signal Inop”

2007 GMC Yukon Multiple Misfires-Codes-P0300-P0352-P0354-P0356-P0358

This 2007 GMC Yukon came in with multiple complaints among which were the engine seemed to have no power, the Service Engine Soon, ABS and Traction lights were on and there was a stability message displayed in the Driver’s Information Center (DIC). The customer also stated that the vehicle ran fine sometimes but as soon as the … Continue reading “2007 GMC Yukon Multiple Misfires-Codes-P0300-P0352-P0354-P0356-P0358”

2011 Cadillac DTS, Battery Goes Dead Overnight

This 2011 Cadillac DTS came in with the complaint that the battery will go dead if the car sits for more than 12 hours. I traced the drain to the Driver’s Door Module fuse (DDM)  in the rear underseat fuse block.  I used an amp meter connected in series between the battery negative terminal and … Continue reading “2011 Cadillac DTS, Battery Goes Dead Overnight”

2004 Chevrolet Tahoe, Compressor Will Not Turn On

This 2004 Chevrolet Tahoe came in with the complaint that the a/c was not cold due to the compressor not coming on. Whenever the a/c was turned on the snowflake on the digital display would flash. This Tahoe has auto a/c controls. I checked codes with my Tech 2 scan tool and there was a … Continue reading “2004 Chevrolet Tahoe, Compressor Will Not Turn On”

2008 GMC Yukon, Reduced Power Mode, Code P0641 00 Stored

This 2008 GMC Yukon came in with the complaint of reduced power and the vehicle could not be driven over about 35 mph. There were a lot of codes stored but the only one of real relevance was Code P0641 Symptom 00, 5 volt reference circuit 1.  I looked at data under the TAC section … Continue reading “2008 GMC Yukon, Reduced Power Mode, Code P0641 00 Stored”

2004 GMC Yukon, Power Windows & Seats Inop, Airbag Light Is On

This GMC Yukon came in with the complaint that the power windows and power seats did not work and the Airbag light was on. Checking the fuses found that the SIR or airbag light 15 amp fuse was blown. I also found that the 50 amp MBEC fuse was blown. I replaced both fuses and … Continue reading “2004 GMC Yukon, Power Windows & Seats Inop, Airbag Light Is On”

2007 Chevrolet Tahoe LT, LBEC2 Fuse #75 Blows

This 2007 Chevrolet Tahoe LT came in with the complaint that the LBEC2 fuse would blow as soon as it was installed. The owner had tried several with the same result. The two symptoms that the owner noticed that pointed them towards a blown fuse was that the power windows and rear HVAC unit did … Continue reading “2007 Chevrolet Tahoe LT, LBEC2 Fuse #75 Blows”