What this code means
P0523 generally means the PCM may be seeing an engine oil pressure sensor signal voltage that is higher than expected.
What the vehicle may do
- The vehicle may store the code when the oil pressure sensor signal voltage is too high.
- The vehicle can sometimes appear to run normally while the fault is present.
- A warning or fault indicator may be possible depending on the vehicle state.
Possible fault areas
- Possible engine oil pressure sensor signal circuit issue
- Possible sensor ground-side issue
- Possible engine oil pressure sensor issue
- Possible wiring or connector concern
- Possible PCM involvement after other checks pass
Diagnostic path
Opening context
On this 2017 to 2025 Honda CR-V with the 1.5 turbo engine, P0523 means the PCM is seeing the engine oil pressure sensor signal higher than it expects. The vehicle may act normally, or it can set a warning and store the code when that signal voltage is too high. Broadly, this can involve the sensor signal circuit, the sensor ground side, the engine oil pressure sensor itself, related wiring or connectors, and in the final stage, the PCM. Start with the basic system checks and follow a structured diagnostic approach before getting into pinpoint testing.
Duplicate the fault
For the confirmation check, turn the vehicle to ON mode and look at the HDS Rocker Arm Oil Pressure, or EOP, Sensor Voltage. If that value is more than 4.79 V, the failure is duplicated. That gives you a live condition to chase instead of guessing from the stored code alone.
Simulate the sensor circuit response
There is no direct component-only test for the engine oil pressure sensor here, so the diagnostic path checks the related circuit behavior. Disconnect the engine oil pressure sensor 3P connector. Then jump terminals No. 1 and No. 2 of that connector with a jumper wire. Turn the vehicle to ON mode again and confirm the HDS Rocker Arm Oil Pressure, or EOP, Sensor Voltage.
Read the simulated result
With that jumper in place, the normal result is less than 4.79 V. If the reading is normal during this check, the diagnostic result points to a problem with the engine oil pressure sensor. If the reading is still abnormal, keep moving down the path because the problem is in another related part of the circuit.
Prepare for circuit continuity checks
Before disconnecting the PCM connector, jump the SCS line with the HDS and wait more than 1 minute. Then disconnect the engine oil pressure sensor 3P connector and PCM connector E, the 80P connector. Do not skip the SCS step before unplugging the PCM side.
Check OPSEN and SG2 for opens
Now perform the OPSEN and SG2 open-wire inspections according to the connector test layout. The normal condition for the OPSEN open-wire check is less than 1 Ω, and the normal condition for the SG2 open-wire check is also less than 1 Ω. If either result is abnormal, the problem is in the circuit.
Final PCM decision point
If the previous inspection items all indicate normal condition, then the remaining diagnostic conclusion is that there is a problem with the PCM. At that point, pause and make sure the earlier path was followed cleanly before making that call. Do not jump to the PCM unless the sensor-side and circuit checks have already passed.
Takeaway and CTA
The key with P0523 is to prove the high sensor-voltage condition first, then use the jumper check and the OPSEN and SG2 continuity checks to separate a sensor-side issue from a circuit issue before considering the PCM. For more diagnostic training, visit stepdiagnostics.com.
Final check
This diagnosis often comes down to proving the high-voltage signal, simulating the sensor circuit response, then checking the related wiring before making a final module-side call.
For more guided automotive diagnostics, visit STEP Diagnostics.
