P1AC9
HCM Service Calibration Fault
P1AC9 is an OBD-II diagnostic trouble code meaning: HCM Service Calibration Fault. Common causes: hcm software failure, calibration update failed. Estimated repair cost: $167–556.
Symptoms
- Check Engine light comes on
- Reduced performance of the hybrid system
- Problems with switching between driving modes
- Increased fuel consumption
- Unstable engine operation
Causes
- HCM software failure
- Calibration update failed
- HCM module malfunction
- Problems with wiring or connectors
- Associated sensors malfunction
How to Fix
- Perform diagnostics using a scanner that supports hybrid systems
- Check the condition of the wiring and connectors associated with the HCM
- Try to reflash the HCM module
- Replace HCM if necessary
- Check and replace faulty sensors if found
Related codes
FAQ
What does the P1AC9 code mean?
P1AC9 is an OBD-II diagnostic trouble code that indicates: HCM Service Calibration Fault
What causes a P1AC9 error code?
The most common causes of P1AC9 include: HCM software failure; Calibration update failed; HCM module malfunction; Problems with wiring or connectors.
How do I fix a P1AC9 diagnostic trouble code?
To fix P1AC9: Perform diagnostics using a scanner that supports hybrid systems. Check the condition of the wiring and connectors associated with the HCM. Try to reflash the HCM module. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P1AC9?
Yes, but get it checked soon
How much does it cost to fix P1AC9?
The estimated repair cost for P1AC9 is $167–556. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat