What this code means
P0842 may indicate that the ICM is seeing a low transmission fluid pressure sensor signal.
What the vehicle may do
- The vehicle may display a warning or store the code after the monitor detects a low signal condition.
- Transmission operation may feel different if the system reacts to the fault.
- The symptom may be intermittent if the signal or circuit problem comes and goes.
Possible fault areas
- A possible transmission fluid pressure sensor signal concern.
- A possible sensor supply or reference circuit concern.
- A possible short-to-ground or open-circuit wiring concern.
- A possible connector or terminal condition issue.
- A possible ICM concern after the related checks are normal.
Diagnostic path
Opening context
P0842 on this 2018–2025 Honda Accord 2.0 Hybrid is an ICM-monitored low transmission fluid pressure sensor signal fault. In plain terms, the module may be seeing the pressure sensor voltage lower than it expects. The vehicle may show a warning, may change how the transmission operates, or may only store the code depending on when the fault shows up. Broadly, think in terms of a possible sensor signal issue, sensor supply circuit issue, short-to-ground issue, wiring or connector problem, and only after the checks prove out, a possible ICM fault.
Confirm the fault is present
Start with the basic system checks and follow a structured diagnostic approach before getting into the pinpoint tests. Then turn the vehicle to ON mode and look at the HDS data for [Oil Pressure Sensor 1 Voltage]. If that value is 0.25 V or less, the failure is duplicated and you can continue down this diagnostic path.
Check the pressure sensor output path
Next, prepare for the transmission fluid pressure sensor inspection by disconnecting the transmission fluid pressure sensor connector, the 3P connector. This path does not give a direct test of the sensor by itself, so the diagnosis proves what the related circuit is doing around it. With IG Mode ON, the unit output voltage normal condition is About 5 V. If that inspection is normal, the fault points to a problem with the transmission fluid pressure sensor. If that inspection is abnormal, keep going because the problem is in the related components or circuit path.
Check VCC2 for an open
For the VCC2 open wire inspection, disconnect the transmission fluid pressure sensor connector, 3P, and ICM connector A, 28P. With IG Mode OFF, the normal condition for the VCC2 open wire check is less than 1 Ω. If that check is abnormal, treat it as a circuit problem before moving any further.
Check PODCL1 for a short to ground
After that, set up the PODCL1 shorted wire inspection by disconnecting the transmission fluid pressure sensor connector, 3P, and ICM connector P, 36P. Use the open or short circuit inspection method for the circuit being checked, then test PODCL1 for a short to ground. With IG Mode OFF, the normal condition is more than 1 MΩ. If that check is abnormal, the fault is in the circuit.
Final isolation and takeaway
If the other inspection items all show normal conditions, the remaining fault area is the ICM. Do not jump there early; get through the sensor output check, the VCC2 open check, and the PODCL1 short-to-ground check in order. If terminal identification is not clear during any table-based check, stop and verify the connector points before probing. Don’t guess. Takeaway: prove the low signal first, isolate the sensor and circuit paths next, and only leave the ICM as the cause after the other inspections are normal. For more diagnostic training, visit stepdiagnostics.com.
Final check
For P0842, the diagnostic logic is to confirm the low sensor voltage, then separate the sensor output path from the supply and short-to-ground circuit checks before considering the ICM.
For more guided automotive diagnostics, visit STEP Diagnostics.
