What this code means
P0087 may indicate that fuel rail pressure is lower than expected for the operating condition being monitored.
What the vehicle may do
- The vehicle may have reduced power.
- The engine may be hard to start.
- The engine may stall or may not start.
- The fault can be intermittent depending on operating conditions.
Possible fault areas
- Possible fuel supply restriction or leak.
- Possible fuel return system issue.
- Possible rail pressure sensor signal or connection issue.
- Possible pressure regulator control issue.
- Possible injector leakage or restriction.
- Possible fuel contamination or poor fuel quality conditionь малой стороне и return/fuel feed issue.
Diagnostic path
Open on what P0087 means
On this 2022 Chevrolet Silverado 2500 with the 6.6 diesel, P0087 is a fuel rail pressure fault. In plain language, the truck may be seeing rail pressure that is lower than the controller expects under the conditions where the monitor runs. The driver may notice reduced power, a hard start, stalling, or a no-start, but the diagnostic path does not start by condemning a pump. The possible fault areas can include fuel supply, return flow, the rail pressure sensor signal, pressure regulators, injectors, fuel quality, leaks, restrictions, or the high-pressure pump. Work it in order and let the pressure data decide where you go next.
Start with basic checks and monitor gates
Start with the basic system checks, then follow a structured diagnostic approach. Before chasing P0087 by itself, make sure the operating gates make sense: the engine has to be running, the low fuel indicator needs to be off, ignition voltage is listed as Greater than 11 V, ambient air temperature is Warmer than −7°C (19°F), and BARO Sensor 2 is Greater than 60 kPa (8.7 PSI). The monitor logic also uses calibrated range timing, including greater than 1 s and greater than 9 s conditions, so treat those as monitor gates, not as a substitute for the actual pressure tests. For this fault group, additional actions can include the starter being disabled for the current drive cycle and the engine going into shutdown mode.
Clear related-code distractions first
With the ignition on and the vehicle in service mode, check for fuel pump driver, fuel pressure sensor, fuel pump, and regulator control related codes. If those are present, check what they mean first and do not shortcut straight into the P0087 pressure routine. If no related code is set, move to the base fuel pressure check with the engine idling.
Check low-side pressure at idle
At idle, look at the scan tool Fuel Pressure Sensor value. The expected range here is 370 to 450 kPa (54 to 65 PSI). If it is less than 370 kPa (54 PSI), go into fuel system diagnosis. If it is greater than 450 kPa (65 PSI), go into fuel return system diagnosis. If it is between 370 and 450 kPa (54 and 65 PSI), reproduce the operating conditions and verify whether P0087 resets. If the code does not reset, this path is all OK. If it does reset, keep going with the next tests in this diagnostic sequence.
If the code returns, inspect the fuel system conditions
Turn the vehicle off and check for the conditions that can make the pressure reading or actual rail pressure wrong. Look for a poor connection or skewed fuel rail pressure sensor signal, leaking or restricted injectors, leaking or restricted fuel rail or feed pipe issues, and contaminated or poor-quality fuel. If one of those conditions is present, repair or replace as necessary. If no condition is found, continue to the commanded regulator checks.
Command the regulators and compare desired to actual rail pressure
With the engine idling, command Fuel Pressure Control Regulator 1 to increase and decrease. Fuel Rail Pressure Sensor 1 should change with each command. If it does not change, replace Fuel Pressure Regulator 1. If it does change, command Fuel Pressure Control Regulator 2 to increase and decrease. Again, Fuel Rail Pressure Sensor 1 should change with each command. If it does not change, replace Fuel Pressure Regulator 2. If it does change, command Fuel Rail Pressure to increase and decrease. The rail pressure maximum at idle is listed as 120 MPa (17,405 PSI), and the decision point here is the comparison: Desired Fuel Rail Pressure and Fuel Rail Pressure Sensor 1 need to be within 2,000 kPa (290 PSI) of each other. If they are not within 2,000 kPa (290 PSI), move into high-pressure side fuel system diagnosis. If they are within 2,000 kPa (290 PSI), the next step in this path is to test or replace the high pressure fuel pump.
Verify and close
After the repair, verify the repair and confirm the code stays gone. Keep the verification separate from the fuel-system testing: first finish the diagnostic branch, then rerun the conditions needed to prove P0087 does not reset. The takeaway is simple: for P0087, do not guess at the high-pressure pump until the related codes, low-side pressure, physical fuel conditions, regulator response, and desired-versus-actual rail pressure have all been checked in order. For more diagnostic training, visit stepdiagnostics.com.
Final check
P0087 is often best handled by checking related faults first, confirming low-side pressure, then using commanded pressure and regulator response to narrow the possible fault area.
For more guided automotive diagnostics, visit STEP Diagnostics.
