Case Study: Acadia no-start, does not crank

April 19, 2023

The Acadia was towed to the shop for a no-start/does not crank concern.

Richard Diegle

Related To: ALLDATA

Case Study: Acadia no start, does not crank

Vehicle: 2009 GMC Acadia, FWD, V6-3.6L, automatic transmission/transaxle

Mileage: 88,720

Problem: The Acadia was towed to the shop for a no-start/does not crank concern.

Case details: The technician attempted to scan for diagnostic trouble codes (DTCs) but found no communication with the engine control module (ECM). He checked for battery power to the ECM. There was none. The technician found that the ECM1 fuse (15A) was blown. He replaced the fuse, but as soon as he turned the ignition key to the "on" position, the fuse blew again.

Using the factory wiring diagram in ALLDATA as a guide, he found the only power supply to the ECM1 fuse was from the ECM itself. He unplugged the ECM and replaced the fuse. This time, turning the ignition switch to the "on" position did not blow the fuse. He load-tested the circuits, between the ECM and ECM1 fuse. They all passed. He determined that the ECM must have been shorted internally.

Confirmed repair: The technician replaced and programmed the ECM. After that, the Acadia cranked, started and ran great… and the ECM communicated normally. Problem solved!

Reprinted with permission from ALLDATA.

About the Author

Richard Diegle | Senior Automotive Editor for ALLDATA

Rich Diegle has been in the automotive industry since 1978. After graduating from a local community college, he began working at a Nissan dealership as a used car technician. Since then, he’s worked as a Nissan and ASE master automotive technician, shop owner, marketing copywriter, automotive editor, public relations manager, instructor, ALLDATA Tech-Assist team manager, and a senior automotive editor.