DTC Advanced Diagnostics: P2623
DTC P2623:High Pressure Fuel Pump Spill Valve Malfunction

General Description

The fuel pressure is adjusted by high pressure fuel pump output ON/OFF which is controlled by the powertrain control module (PCM). In the PCM, the injector driver receives drive commands from the CPU and drives the high pressure fuel pump. The CPU monitors high pressure fuel pump currents and return signal from the injector driver to monitor a terminal voltage of PCM. If the monitored conditions are abnormal for a specified time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
–
DTC Type
One drive cycle, MIL on

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [BATTERY]
10 V
–
Vehicle
ON mode
[ ]: HDS Parameter

Malfunction Threshold
Either of the conditions occurs at least 100 times (counts 4 times per engine cycle):
Symptom: High pressure fuel pump current not flowing
The pump solenoid current is 0.4 A to 1.5 A or less*.
Symptom: High pressure fuel pump overcurrent
The pump solenoid current is 19.7 A to 30.5 A or more*.
Symptom: PCM terminal (to high pressure fuel pump) short to ground
The PCM terminal (to high pressure fuel pump) voltage is 1.8 V to 2.2 V or less*.
Symptom: PCM terminal (to high pressure fuel pump) short to power
The PCM terminal (to high pressure fuel pump) voltage is (12 volt battery voltage - 3.2) V to (12 volt battery voltage - 2.2) V or more*.

*: Varies with driving condition.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
High pressure fuel pump failure
High pressure fuel pump HPUMP H line open
High pressure fuel pump HPUMP H line short to ground
High pressure fuel pump HPUMP H line short to power
High pressure fuel pump HPUMP L line open
High pressure fuel pump HPUMP L line short to ground
High pressure fuel pump HPUMP L line short to power
Injector relay failure
PCM internal circuit failure (injector driver power supply line open)

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.