P1603
8 owner reports and 15 manufacturer filings across 14 model years from Hyundai, Subaru, Toyota.
Where P1603 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2018 Toyota RAV4 | Electrical System | — | 4 |
| 2020 Hyundai Elantra | Power Train | 3 | — |
| 2021 Hyundai Accent | Electrical System | 2 | — |
| 2020 Hyundai Accent | Electrical System | 2 | — |
| 2017 Toyota Highlander | Fuel System, Other | 2 | — |
| 2016 Toyota Highlander | Fuel System, Other | 2 | — |
| 2026 Hyundai Venue | Unknown Or Other | 1 | — |
| 2021 Hyundai Venue | Power Train | 1 | — |
| 2020 Hyundai Venue | Power Train | 1 | — |
| 2018 Subaru Crosstrek | Engine | — | 1 |
| 2017 Subaru Legacy/Outback | Engine | — | 1 |
| 2020 Toyota Corolla | Fuel System, Gasoline | — | 1 |
| 2017 Toyota Corolla | Engine | — | 1 |
| 2018 Toyota Highlander | Electrical System | 1 | — |
A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.
What it gets filed under
What owners said
Source: NHTSA complaint databaseOwners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.
The mechanic retrieved DTC: P1603; "Engine Stall History" (ECM recording an unexpected engine shutdown or a communication error with the Transmission Control Module (TCM)
3 trouble codes were recorded p1603(engine stall), P1604 startability malfunction, and p1605(rough idling), however they were unable to determine root cause of stalling and refused to keep my car to do further analysis despite the fact…
The dealer performed diagnostic and fuel testing, which produced a code of P1603 and a good fuel reading; however, the contact was advised to use a different fuel station
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P1603. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.
- 24-01-018H2024-02-23 · Electrical System
- Certain 2020-2021MY Accent (HC) vehicles may experience an illuminated warning light due to the following Diagnostic Trouble Codes (DTC) listed below: ⢠TCU DTC Codes: P0730, P0731, P0741, P0867, P1603 Follow the procedure in TSB 24-01-018H (or latest version) to perform the TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition.
- 24-01-014H2024-02-21 · Electrical System
- Certain 2020-2021MY Accent (HC) vehicles may experience an illuminated warning light due to the following Diagnostic Trouble Codes (DTC) listed below: ⢠TCU DTC Codes: P0730, P0731, P0741, P0867, P1603 Follow the procedure in TSB 24-01-018H (or latest version) to perform the TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition.
- 23-01-019H2023-03-15 · Unknown Or Other
- Certain 2020-22MY Venue (QX) vehicles may experience a check engine light or malfunction indicator light due to Diagnostic Trouble Codes (DTC) listed below. Perform the TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition. ⢠TCU DTC Codes: P0730, P0731, P0741, P0867, P1603
- 22-01-030H2022-03-21 · Power Train
- Certain 20MY Elantra (AD/ADa) vehicles may experience an illuminated check engine warning light due to Diagnostic Trouble Codes (DTC) listed below. Perform the Transmission Control Unit (TCU) update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition. This update also includes the software for optimizing CLR_DIST (distance traveled since DTCs clear
- Campaign T5B Dea2020-06-24 · Power Train
- Certain vehicles may experience an illuminated warning light due to Diagnostic Trouble Codes (DTC). This service campaign provides information on the procedures to perform the ECU and TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition. ⢠TCU DTC Codes: P0730, P0731, P0741, P0867, P1603 ⢠ECU DTC Codes: P0106, P0068, P0101
- 20-01-028H2020-06-24 · Power Train
- Certain vehicles may experience an illuminated warning light due to Diagnostic Trouble Codes (DTC). Perform the ECU and TCU update, and, if necessary, replace the IVT (Intelligent Variable Transmission) to resolve this condition. ï· TCU DTC Codes: P0730, P0731, P0741, P0867, P1603 ï· ECU DTC Codes: P0106, P0068, P0101
What P1603 means
Source: SAE J2012 / OBD-IIP1603 is a manufacturer-specific code: the second character is a 1, which under the OBD-II standard hands the definition to whoever built the vehicle. The same code can mean one thing on a Ford and something unrelated on a Hyundai. Any site that prints a single definition for it is guessing.
A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.
Common questions about P1603
Source: NHTSA files and the OBD-II standardWhy does this page not define P1603?
Because it cannot be defined honestly. The second character of a trouble code says who owns its meaning, and a 1 or a 3 hands that to the manufacturer. Sites that print one definition for a manufacturer-specific code are showing you one automaker's meaning and hoping it is yours.
Can I keep driving with P1603 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light generally means the fault was logged and the vehicle is in a reduced-risk mode; a flashing light means stop soon, because a misfiring engine can destroy a catalytic converter in minutes. The safe read of this page is the mileage and the components, not permission.
Does a code mean the car is recalled?
No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.
Why do the counts here differ from other sites?
Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.
Will clearing the code fix it?
Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.