The P1637 code on your 2021 Buick Enclave indicates a problem with the engine oil life monitoring system reset circuit. This GM-specific code affects your Enclave's 3.6L V6 engine's oil life monitoring system, which calculates oil change intervals based on driving conditions and engine operation.
Understanding P1637 on Enclave
GM's oil life monitoring system uses algorithms based on engine temperature, RPM, load, and other factors to calculate remaining oil life percentage. The reset circuit allows the system to be reset after an oil change. Code P1637 sets when there's an electrical fault in this reset circuit or communication issue with the oil life monitoring system.
Common Symptoms
- Check engine light on
- Oil life monitor won't reset after oil change
- Oil life percentage stuck at a value
- Change oil message always displayed
- Oil life readings inaccurate
- Driver information center communication issues
Primary Causes
- Body control module communication fault
- Instrument cluster issue
- Wiring problem in reset circuit
- PCM to BCM communication error
- Aftermarket device interfering with data bus
- Software/calibration issue
- Damaged reset switch if equipped
Diagnostic Procedure for 2021 Enclave
Begin by attempting to reset the oil life monitor using the standard procedure (consult owner's manual). If reset fails, use a GM scan tool to command oil life reset. Check for communication codes between modules. Verify data bus communication between PCM, BCM, and instrument cluster. Inspect wiring to the reset switch if equipped with a physical button. Check for aftermarket devices connected to the OBD-II port that may interfere with module communication.
Repair Solutions
Remove any aftermarket OBD-II devices and clear codes to test. Repair any damaged wiring in the communication circuits. If the instrument cluster has internal faults, replacement or repair may be needed. Update software if a TSB applies. Verify proper module communication after repairs. Reset oil life using proper procedure and verify the monitor functions correctly.