P0603 on Infiniti vehicles The engine control module has lost its keep-alive memory
P0603 is named on 36 Infiniti model years (2016–2021): 42 manufacturer filings and 0 owner reports in NHTSA’s files, across Q50, Q70, QX50, QX60, QX70 and 3 more.
Which Infiniti model years name P0603
Source: NHTSA manufacturer communications and complaintsA model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.
Infiniti filings that name P0603
Source: NHTSA manufacturer communicationsBulletins and campaigns Infiniti filed with NHTSA whose summary names P0603. Quote the document number at the service desk — it is a diagnosis the maker has already written down.
- ITB16008 Service bulletin2016-02-22 · Electrical System
- IF YOU CONFIRM The MIL is "ON" with DTC P0603 (ECM BACK UP/CIRCUIT). ACTION 1. Confirm that the battery voltage is 11 volts, or more, with the ignition ON (engine OFF, not running). 2. Erase DTC 3. Perform DTC confirmation steps in the Service Procedure. 4. Confirm 1st trip DTC P0603 is not stored. NOTE: P0603 is often the result of low battery voltage
- ITB21-007 Service bulletin2021-04-01 · Engine And Engine Cooling
- MIL ON WITH DTC P062F AND/OR P0603 STORED IF YOU CONFIRM The MIL is ON and DTC P062F (EEPROM) and/or P0603 (ECM BACK UP/CIRCUIT) is stored, And The customer stated the vehicle was recently started after sitting for an extended period of time (i.e., the battery voltage was low while attempting to start the engine). ACTION 1. Test the vehicleâs 12 volt battery using the Midtronics DSS-500
- ITB16-008C Service bulletin2021-04-01 · Engine And Engine Cooling
- MIL ON WITH P0603 STORED FOR ECM BACK UP CIRCUIT This bulletin has been amended. See AMENDMENT HISTORY on page 3. Please discard previous versions of this bulletin.
What P0603 means
Source: SAE J2012 / OBD-IIThe engine control module has lost its keep-alive memory.
A stored code names the test that failed, never the part that caused it. The record above is what Infiniti and its owners have filed about it; the code’s page across every make has the whole file.
Common questions
Source: NHTSA files and the OBD-II standardIs P0603 a known problem on Infiniti vehicles?
It is a documented one: NHTSA's files hold 42 manufacturer filings and 0 owner reports naming P0603 on 36 Infiniti model years (2016–2021). Whether it is a problem on one particular car is a diagnosis, not a count — but a bulletin that names the code on your model year is the place to start.
Which Infiniti models does P0603 appear on most?
2016 Q50 (2 documents), 2016 Q70 (2 documents), 2016 QX50 (2 documents).
Does P0603 on a Infiniti mean it is recalled?
No. Recalls are filed by campaign and matched by VIN; no recall is triggered by a scan tool. Check the VIN at nhtsa.gov/recalls, or open the model year's page here for the campaigns filed against it.