This book has a new updated version, for the updated version click here.
Scan tools don’t fix cars. You do! In fact, there are times when the Scan tool and a flowchart will tell you to stop looking at the data and change a part. Also, it’s easy to get lost in the vast amount of available data on today’s automobiles.
This manual will teach you how to leverage the available Scan Tool functions both stand-alone and in conjunction with physical and circuit tests. It won't teach you how to navigate any particular scan tool. But it will explain how to take control of the diagnostic flow, allowing you to quickly drill down to a root cause.
This manual isn’t about bizarre diagnostics you’ll never see – it’s about a repeatable thought process you can use to find faults that the flowchart can’t, and to find all faults faster. There are dozens of examples of this strategy in action, diagnosing the most common faults:
• Fuel Trim codes
• EVAP leak and other functional failure codes
• O2 and Air/Fuel sensor codes
• Misfire code isolation techniques
• EGR functional and flow codes
• Body & Chassis codes
• Scan Tool ‘No-Communication’ faults
Excerpt: Wiper Malfunction
A 2011 Chevrolet Malibu came in from a used car lot with the complaint that the wipers operated at high speeds even when the wiper switch was in the low speed or intermittent positions. The vehicle had just been purchased at auction with the problem, so no history was available.
Codes? Nope. No codes were stored in any module.
Flowchart? Yes, there was a flowchart for no-code wiper concerns, and after 19 time-consuming circuit-testing steps, the chart said to replace the #2 wiper relay – no change.
What Now?
What simple fault actually caused this complaint? In this case the flow chart was big time waster.
This manual will teach what to review before using the scan tool, what to check with the scan tool, and how to verify the thoroughness of the information you have gathered to help you beat flowchart time and locate the faults the flow charts can't.
