What this code means
P2564 means the ECM/PCM may be seeing a turbocharger wastegate actuator position feedback signal that is lower than expected.
What the vehicle may do
- The vehicle may have reduced boost or weak acceleration.
- A warning light may be present.
- The vehicle can feel limited in power depending on how the fault is handled.
Possible fault areas
- The turbocharger wastegate actuator position sensing area may be involved.
- Wiring, connector condition, opens, or shorts can be possible fault areas.
- The ECM/PCM may be considered only after the related inspections indicate normal conditions.
Diagnostic path
Code overview and diagnostic direction
On this Civic 1.5 turbo, P2564 means the ECM/PCM may be seeing the turbocharger wastegate control actuator position sensor signal too low. In plain terms, the computer may not be happy with the feedback signal from the wastegate actuator position circuit. The vehicle may show reduced boost, weak acceleration, a warning light, or a limited-power feel. The possible fault area can be the turbocharger wastegate actuator position sensing circuit, the related wiring and connectors, or, after the circuit checks prove out, a possible ECM/PCM issue. The key here is not to guess at the turbo. Confirm the low signal first, then separate a turbo-side problem from a circuit-side problem.
Start clean, then confirm the failure
Before getting into the code-specific checks, start with the basic troubleshooting setup and follow a structured diagnostic approach. Then begin the confirmation with the vehicle in ON mode. On the HDS, watch the EWG Voltage From Lift Sensor data. If that value is less than 0.16 V, the failure is duplicated. That tells you the low feedback signal is present during the confirmation check.
Check the turbocharger-side signal
For this position sensor, there is no direct component test for the sensor itself. The diagnostic path is built around checking the related components and circuits. Disconnect the turbocharger 5P connector, then perform the inspection at the disconnected turbocharger 5P connector female terminals with IG Mode ON. The normal unit output voltage for this inspection is About 5.0 V.
Use the first result to split the path
Now use that turbocharger-side inspection result to choose the direction. If the inspection is normal, the diagnostic result points to a problem with the turbocharger. If the inspection is abnormal, stay with the related components and circuits instead of condemning the turbocharger.
Prepare for circuit inspection safely
Before disconnecting the PCM connector for the VCC2 and DCWGL circuit inspection, jump the SCS line with the HDS and wait more than 1 minute. After that, disconnect the turbocharger 5P connector and disconnect PCM connector E, the 80P connector. This setup is for the circuit checks with IG Mode OFF.
Inspect VCC2 and DCWGL circuits
With the turbocharger 5P connector and PCM connector E disconnected, perform the VCC2 and DCWGL circuit inspection with IG Mode OFF. For the VCC2 open-wire inspection, the normal condition is less than 1 Ω. For the DCWGL short-to-ground inspection, use the open and shorted wire inspection method for the shorted circuit, then test according to the condition you find. The normal result for that check is not shorted.
Evaluate the circuit result
If the VCC2 or DCWGL circuit inspection is abnormal, the problem is in the circuit. At that point, stay focused on the wiring path, connector condition, and the specific open or short result you measured.
Only then consider the PCM
If the other inspection items all show a normal condition, the remaining diagnostic conclusion is a problem with the PCM. That is the end of the fault isolation path for this code, not the starting point.
Close and verification mindset
Keep verification separate from testing: once the fault area has been corrected, verify the repair and confirm the code stays gone. The takeaway is simple: for P2564, prove the low lift-sensor voltage, check the turbocharger-side signal, then work through the VCC2 and DCWGL circuits before blaming the PCM. For more diagnostic training, visit stepdiagnostics.com.
Final check
P2564 is often approached as a command-versus-feedback style boost control circuit diagnosis: confirm the low feedback signal, then separate turbocharger-side findings from circuit-side findings.
For more guided automotive diagnostics, visit STEP Diagnostics.
