P0638 on the 2017 Mazda CX-9
The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.
Nobody has written a description of this code yet.
| 01-001-20-3650 | 2020-01-23. Service bulletin. After parking the vehicle in temperatures below freezing, some customers may experience a lack of power with the check engine light on and DTCs P0638:00 and/or P2112:00 stored in memory. - P0638:00: Throttle valve actuator control range/performance problem (one drive cycle DTC) - P2112:00: Throttle valve actuator motor current range/performance problem (one drive cycle DTC) This concern may be caused by condensation in the intake manifold entering the throttle valve. After parking the vehicle in temperatures below freezing, the throttle valve may become frozen in the stand-by position, resulting in the symptoms listed above. To prevent this concern, the control logic of the PCM has been modified to avoid freezing the throttle valve by moving the valve at a certain time after the ignition has been turned off. NOTE: With this modification, the main relay may stay on up to 90 minutes after the ignition switch is turned off. The “BATTERY INSPECTION” area in the Workshop Manual will be modified to properly check for battery parasitic draw after this modification. NOTE: This Service Information is most likely applicable if the concern can be resolved by turning the ignition switch on/off when the vehicle is parked in a warmer location, such as a shop or garage. |
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| 01-001-18-3419a | 2018-09-10. Service bulletin. After parking the vehicle at temperatures below the freezing, some customers may experience a lack of power with the check engine light on and DTC P0638:00 and/or P2112:00 stored in memory. - P0638:00: Throttle valve actuator control range/performance problem (one drive cycle DTC) - P2112:00: Throttle valve actuator motor current range/performance problem (one drive cycle DTC) This concern may be caused by condensed water in the intake manifold entering the throttle valve. After parking at temperatures below freezing, the throttle valve may be frozen at the stand-by position, resulting in the symptom. To prevent this concern, the control logic of the PCM has been modified to avoid frozen the throttle valve (by moving the valve at a certain time after the ignition has been turned off). NOTE: With this modification, the main relay may stay on up to 90 minutes after the ignition switch is turned off. "BATTERY INSPECTION" in the Workshop Manual will be modified to properly check the battery parasitic draw after this modification. |
| 01-001-18-3419 | 2018-03-05. Service bulletin. After parking the vehicle at temperatures below the freezing, some customers may experience a lack of power with the check engine light on and DTC P0638:00 and/or P2112:00 stored in memory. - P0638:00: Throttle valve actuator control range/performance problem (one drive cycle DTC) - P2112:00: Throttle valve actuator motor currentrange/performance problem (one drive cycle DTC) This concern may be caused by condensed water in the intake manifold entering the throttle valve. After parking at temperatures below freezing, the throttle valve may be frozen at the stand-by position, resulting in the symptom. To prevent this concern, the control logic of the PCM has been modified to avoid frozen the throttle valve (by moving the valve at a certain time after the ignition has been turned off). NOTE: With this modification, the main relay may stay on up to 90 minutes after the ignition switch is turned off. "BATTERY INSPECTION" in the Workshop Manual will be modified to properly check the battery parasitic draw after this modification. |
3 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.