ACtion Magazine - June 2013 - (Page 22)

Photo: GM by Bob Pattengale T The second step in the diagnostic process is connecting a scan tool, retrieving the diagnostic trouble codes (DTC) and documenting the data. Figure 1 (page 23) shows two fault codes, B0414 (Temperature Control 1 Feedback Circuit Range/ Performance) and B3770 (Air Flow Control 6 Feedback Circuit). Depending on your knowledge of this system, you might decide to look at scan data or maybe even attempt a few bi-directional controls to determine the cause of the failure, but in the end you still need to move to the third step, which is researching the issue. In the research phase, you should review all available data related to the fault code. If you’re not familiar with the system, start with the description and operation sections. Next, review all related TSBs, and if the module is reprogrammable, determine if he customer arrived in a 2005 Chevrolet Silverado with manual climate control, saying she was unable to get air from the dash vents no matter how the controls were set. The tech noticed that air would flow from the defrost vents but it wasn’t getting cold even though the A/C compressor would engage and run. Where would your diagnostic process begin? Do you depend on past experience and recommendations from others, or do you follow a systematic process to ensure success the first time? The first step in any diagnostic process is verifying the complaint. In this case the customer complaint is verified, and based on how the system is acting you know the climate control system is operating in a default mode. For safety reasons, the climate control system defaults to defrost mode to ensure the windshield can be cleared. 22 ACTION • June 2013

Table of Contents for the Digital Edition of ACtion Magazine - June 2013

ACtion Magazine - June 2013
Freeze Frame
Virtual View
Under the Southern Cross
Leonard's Law
News & Updates
Air Flow Out of Control
Customer Education
Association News
Quick Check
New Products & Services
Last Watch

ACtion Magazine - June 2013