What this code means
P0045 may mean the ECM/PCM is detecting an issue in the turbocharger wastegate control actuator circuit.
What the vehicle may do
- The vehicle may turn on the check engine light.
- The vehicle can have reduced boost or weaker acceleration.
- The concern may be intermittent depending on circuit condition and operating state.
Possible fault areas
- A possible issue with the turbocharger wastegate actuator circuit.
- Possible wiring or connector problems between the turbocharger connector and PCM.
- A possible PCM-side issue after the actuator and circuit checks are normal.
Diagnostic path
Opening context
On this 2017 to 2025 Honda CR-V with the 1.5 turbo engine, P0045 points to the ECM/PCM watching the turbocharger wastegate control actuator circuit and seeing actuator current outside the range it expects. The driver may notice a check engine light, reduced boost, or weak acceleration, but treat those as clues, not a diagnosis. The possible fault areas are the wastegate actuator inside the turbocharger assembly, the actuator wiring and connectors, or, after the other checks pass, the PCM side of the circuit.
Set up the diagnostic path
Start with the basic system checks and follow a structured diagnostic approach before jumping into circuit testing. This code is about command-and-response on the wastegate actuator circuit: if the actuator current is out of its specified range, the PCM flags the fault. First, start the engine. Hold engine speed at 3,000 rpm with no load, in Park or Neutral, until the radiator fan comes on, then let it idle for 2 minutes. After that, run the Electric Waste Gate function with the HDS.
Inspect the wastegate actuator side first
Next, move to the turbocharger wastegate control actuator component inspection. Prepare for that by disconnecting the turbocharger 5P connector. Perform the actuator component inspection using the specified table. In IG Mode OFF, the actuator internal circuit should read About 1.2 Ω - 1.0 kΩ, and the OFF-state short checks should show not shorted. Before probing, make sure the connector view and exact terminal callouts are positively identified. If you cannot identify the correct terminals for the table test, stop and do not guess.
Decide from the actuator result
Evaluate that component inspection before moving on. If the turbocharger wastegate control actuator inspection is abnormal, the diagnostic path points to a problem with the turbocharger. If that inspection is normal, continue into the harness and PCM connector checks instead of condemning parts early.
Prepare for circuit testing
Before disconnecting the PCM connector, jump the SCS line with the HDS and wait more than 1 minute. Then prepare for the WGMTR1 positive and WGMTR2 negative circuit inspection by disconnecting the turbocharger 5P connector and PCM connector E, which is the 80P connector.
Check the WGMTR circuits
Now inspect the WGMTR1 positive and WGMTR2 negative circuits in the order given by the test table. With IG Mode OFF, the WGMTR1 positive open-wire inspection should show less than 1 Ω. The WGMTR2 negative open-wire inspection should also show less than 1 Ω. Then check for the two wires shorted to each other; with IG Mode OFF, that should show more than 1 MΩ. For the short-to-ground checks, use the proper open and short circuit testing method before measuring. WGMTR1 positive shorted to ground should show more than 1 MΩ, and WGMTR2 negative shorted to ground should also show more than 1 MΩ. Again, confirm the connector views and terminal callouts before probing; if the return point or probe points are unclear, pause, recheck the earlier diagnostic path, and avoid guessing.
Final decision and close
Evaluate the WGMTR circuit inspection next. If that circuit inspection is abnormal, the problem is in the circuit. Only if the earlier inspection items are normal do you move into PCM inspection. At that point, the remaining diagnostic path determines the PCM is the cause, and the PCM inspection result is evaluated as a PCM problem. Keep verification separate from the pinpoint testing: after the found fault is corrected, verify the repair and confirm the code stays gone. The takeaway is simple: warm it up, command the wastegate, test the actuator, test the two control wires, and only then consider the PCM. For more diagnostic training, visit stepdiagnostics.com.
Final check
P0045 is often approached by confirming the operating condition, commanding the wastegate actuator, checking the actuator, then checking the control circuits before considering the PCM.
For more guided automotive diagnostics, visit STEP Diagnostics.
