What it means
The generator control module reports a generic fault. Internal self-tests fail or response time outside calibration.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The generator control module manages the generator's role in the hybrid powertrain, including its contribution to electrical power and charging. This code identifies a fault reported by that module, such as a failed internal self-check or a response or communication problem; the exact fault depends on the vehicle's supporting codes and data.
Common causes
Most likely first.
- Internal module fault
- Communication degraded
Symptoms
- Hybrid system warning light on
- Reduced hybrid power or vehicle may not enter READY mode
- Possible loss of generator-assisted charging
How to diagnose it
- Record freeze-frame data and retrieve all hybrid-system codes from every available control module before clearing codes.
- Check scan-tool data for generator status and module communication to see whether the generator module is responding.
- Inspect the generator control module's accessible connectors and harness for looseness, corrosion, or visible damage.
- Check the module's power, ground, and communication circuits using the vehicle wiring diagram and manufacturer's test procedure.
- If the circuits and connections are sound, follow the manufacturer's diagnostic information to assess module self-test results and software status.
Common fixes
- Secure loose generator control module connections and repair corroded terminals.
- Repair faults in the module's power, ground, or communication wiring.
- Apply a manufacturer-approved software update if diagnostic information identifies one as applicable.
- Replace the generator control module if its internal fault is confirmed after circuit checks.
Can I keep driving?
The vehicle may have reduced hybrid power or fail to enter READY, and generator-assisted charging may be unavailable. Avoid relying on it for a long trip; if it will not enter READY or shows additional hybrid warnings, stop safely and arrange assistance.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.