P0AC4

Hybrid/EV Powertrain Control Module Requested MIL Illumination

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–278 (est.)

Symptoms

Check Engine Light Is On
Reduced power or performance
Battery charging problems
Unusual noises from the hybrid system
Increased fuel consumption (for hybrids)

Causes

Malfunction of the hybrid system control module
Problems with high voltage battery
Regenerative braking system malfunction
Damage to wiring or connectors
Software error in PCM

How to Fix

Read all stored trouble codes
Check the condition of the high-voltage battery
Inspect the wiring harness and connectors for damage.
Update PCM Software
Conduct professional diagnostics of the hybrid system

Related codes

P0AC0 P0AC1 P0AC5