Infiniti Circuit Issue

Dec. 29, 2021

This bulletin applies to 2015 Infiniti Q50, Q60 and QX60, 2015-2019 Q70, 2015-2017 QX50 and 2015-2017 QX70 vehicles.

This bulletin applies to 2015 Infiniti Q50, Q60 and QX60, 2015-2019 Q70, 2015-2017 QX50 and 2015-2017 QX70 vehicles. The warning light may be on, with diagnostic trouble code (DTC) P0603 (ECM back up/circuit).

P0603 is often the result of a low battery voltage, a discharged battery or poor battery terminal connections.

Confirm that battery voltage is 11 volts or more with the ignition on/engine off. Resolve any battery issues before proceeding.

Connect the C-III plus VI to the vehicle.

Open C-III plus on the Consult PC.

Turn the ignition on but do not start the engine.

Erase the DTC.

Turn the ignition off.

Turn the ignition on and wait for at least one second.

Turn the ignition off and wait for at least 10 seconds.

Repeat steps 7 and 8 10 times and then proceed to step 10.

Turn the ignition on. If P0603 is currently stored as a first trip DTC, refer to the ESM for further diagnostics. If DTC P0603 is not currently stored as a 1st trip DTC, the service procedure is complete.

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

About the Author

Mike Mavrigian | Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of  specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.

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