Engine Mount "A" Control Circuit High
The P0A16 code means the vehicle's onboard diagnostic system has detected: Engine Mount "A" Control Circuit High. This is a minor severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $100 - $700 (control wiring at the low end; an active engine mount at the high end)
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Common Symptoms
- Check Engine Light on
- Increased vibration at idle or during engine start/stop transitions
- No other drivability effect
Probable Causes (Ranked by Likelihood)
- Failed active engine mount actuator (Engine Mount "A") High
- Open or shorted mount control wiring, or a corroded connector High
- Vacuum leak to the mount on vacuum-switched designs Moderate
Frequently Asked Questions
What does P0A16 mean?
P0A16 means the control circuit for the Engine Mount "A" is faulty. Hybrids use switchable mounts to absorb the engine's frequent start/stop cycles.
Can I keep driving with P0A16?
Yes - this is a comfort system. You will feel more vibration, but nothing about the hybrid drivetrain is at risk. Fix at your convenience.
Is P0A16 safe to work on myself?
This code involves the high-voltage system. Do not open the HV battery, inverter, or any orange-cabled component without hybrid-specific training, insulated gloves, and the service plug removed. Diagnosis beyond a scan-tool read belongs at a hybrid-qualified shop.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Confirm the symptom: active-mount faults show up as idle shake, strongest when the engine starts and stops in hybrid operation.
-
Inspect the Engine Mount "A" wiring and connector.
-
Command the mount with a scan tool where supported and feel/listen for the change.
-
Inspect the mount itself for tears or fluid leakage.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- Toyota/Lexus hybrids (Prius, Camry Hybrid, RAV4 Hybrid)
- Ford/Lincoln hybrids (Escape, Fusion, C-MAX)
- Honda hybrids (Insight, Civic Hybrid, Accord Hybrid)
- Hyundai/Kia hybrids and plug-in hybrids
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