Infiniti (and beyond) DTC P0603
This TSB applies to 2006-2008 Infiniti FX (S50), 2009 FX (S51), 2006 G35 Sedan (V35), 2006-2007 G35 Coupe (CV35), 2007-2008 G35 Sedan (V36), 2008-2009 G37 Coupe (CV36), 2009 G37 Sedan (V36), 2006-2009 M (Y50), 2008 EX35 (J50) and 2006 Q45 (F50), that displays MIL ON and a DTC P0603 stored in the ECM.
The DTC may have been stored due to a series of low battery voltage, dead battery or battery terminal disconnections. Do not perform any other diagnostic procedures or repairs for this code until you have performed the procedures outlined in this bulletin.
Connect CONSULT III to the vehicle’s diagnostic connector.
Turn the ignition switch to the ON position but do not start the engine.
Check for DTCs. Confirm that DTC P0603 is stored. If additional DTCs are stored, document the DTCs before proceeding.
Erase all DTCs and confirm that no DTCs are now stored.
Turn the ignition switch OFF. Wait exactly five minutes after the display changes from “No DTC” to “Error.” NOTE: This waiting period is necessary for the ECM to completely shut off. Do not disconnect the battery cable at any time during this procedure.
Turn the ignition to the ON position but do not start the engine. Wait 10 seconds after the display changes from “Error” to “No DTC.”
Repeat step 5 and 6 five more times to complete the system check.
If DTC P0603 does not display after the system check, this will indicate P0603 was caused by : a series of previous low battery voltage, dead battery or battery terminal disconnections, and that the vehicle harness, connections and ECM are operating properly. Do not replace the ECM. No further action is necessary concerning DTC P0603. If other DTCs were previously stored, refer to the appropriate Electronic Service Manual for further assistance for those DTCs.
If DTC P0603 does display after the system check, refer to the appropriate Electronic Service Manual for further DTC P0603 diagnostic assistance.