P0088 - FUEL RAIL/SYSTEM PRESSURE - TOO HIGH
Description of DTC code P0088
When DTC code P0088 OBD2 is set it is because the Powertrain Control Module (PCM) has detected an excessive level of input voltage from the Fuel Rail Pressure Sensor (FRP) or a very high pressure on the fuel rail.
The FRP sensor has a reference signal of 5 volts. In addition, it has a ground signal. If the fuel pressure increases, the resistance of the sensor decreases. When fuel pressure rises and sensor resistance drops, the signal voltage from the sensor to the PCM must increase accordingly, with 4.5 being the maximum voltage.
To achieve efficient fuel consumption, the FRP sensor adjusts the voltage of the fuel pump, seeking to achieve the necessary amount of pressure on the fuel rail. If the fuel rail pressure is higher than the amount programmed in the PCM, diagnostic code P0088 is stored.
Symptoms of fault code P0088
- MIL (Check Engine) light on.
- If the engine is cold, there is a delayed start.
- Lower fuel efficiency.
- Other fault codes related to misfiring can be set.
Causes of OBD2 P0088
A fault code P0088 OBDII can be set due to:
- Faulty cables or connectors may be present in the Fuel Rail Pressure (FRP) sensor circuit.
- Faulty FRP
- Perhaps the fuel regulator is in bad condition.
- Bad programming of the Powertrain Control Module (PCM).
Possible solutions of the DTC code P0088
DTC code P0088 OBD2 troubleshooting repairs are as follows:
- Refer to the TSB (Technical Service Bulletins).
- Check electrical components, such as circuit cables and connectors. If there are inconsistencies in one of these, repair it or replace the component if necessary.
- If the intake manifold vacuum is used to control the fuel rail pressure, you should consult the appropriate service manual for your vehicle for specifications of this vacuum. Make sure the level is within those specifications.
- Check the actual fuel pressure and if it is higher than recommended by the manufacturer, the fuel pressure regulator may be defective. If on the other hand the fuel rail pressure is within specifications, the FRP sensor may be in poor condition.