Chevrolet Equinox Service Manual: #PIT5200A: HVAC Blows Cold Due To Low System Voltage Or DTC B101E Symptom 4B - (Nov 8, 2013)

Subject:	HVAC Blows Cold Due To Low System Voltage Or DTC B101E Symptom 4B
Models:	2010 - 2014 Chevrolet Equinox
	2010 - 2014 GMC Terrain
	with Auto HVAC System (RPO C68)

This PI was superseded to update model years and diagnostic info. Please discard PIT5200.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) describedin this PI.

Condition/Concern

Customers may comment on the HVAC system will start blowing cold air without beingrequested. This condition was found on the C68 auto HVAC system.

Example: Customer set temperature to 76 degrees F and while driving the HVAC changesto cold and unable to increase temperature when moved to full hot.

A Technician may find either no DTCs or DTC B101E symptom 4B. NOTE: DTC B101E is setwhen a temperature or mode actuator has lost its learn position, is out of range,or is inoperative. This concern may also occur when system voltage is low.

Recommendation/Instructions

Recent field cases found the cause to be low system battery voltage due to corrosionat the starter connections.

For vehicles that exhibit this condition and when the condition is present, use GDSand select "Remote Heater and Air Conditioning Module", select "HVAC System Data",and check the "Ignition Voltage" parameter. If voltage is less than 12 volts, inspectfor signs of corrosion at the starter stud battery cable connections. Clean and recheckbattery charging voltage.

For situations in which DTC B101E is set and Ignition Voltage is greater than 12 volts,perform the following:

Operate the HVAC recirculation to fresh air mode, vent position modes and operatetemperature from hot too cold to see if the modes will change in all positions. Example:The temperature remains cold and GDS reflects the counts remain at zero (0).Using GDS, perform the Actuator Calibration Learn procedure. Under “HVAC Door PositionData 1”, check for actuators that are not learned. Example: The left temperature actuatoris not learned and does not move. After checking for a mechanical bind, suspect afaulty connection at the suspect temperature actuator.Warranty Information

For vehicles repaired under warranty use:

Labor Operation 

Description

Labor Time

5480048*	Check Ignition System Voltage and Clean Positive Battery Cable Terminal at Starter	0.3 hr
4480088*	Actuator Calibration Learn Procedure	0.3 hr
* This is an unique labor operation for bulletin use only. This will not be publishedin the Labor Time Guide.

For wiring repairs covered under warranty, please refer to latest version of bulletin10-00-89-005 for warranty information on wire/connector repairs.

Please follow this diagnostic or repair process thoroughly and complete each step.If the condition exhibited is resolved without completing every step, the remainingsteps do not need to be performed.

GM bulletins are intended for use by professional technicians,NOT a "do-it-yourselfer".  They are written to inform thesetechnicians of conditions that may occur on some vehicles, or toprovide information that could assist in the proper service of avehicle.  Properly trained technicians have the equipment,tools, safety instructions, and know-how to do a job properly andsafely.  If a condition is described, DO NOT assume that thebulletin applies to your vehicle, or that your vehicle will havethat condition.  See your GM dealer for information on whetheryour vehicle may benefit from the information.

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