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DTC P0628: Fuel Pump (high pressure) Control Circuit Low
 
 
 
 
CIRCUIT OPERATION
  • The voltage is applied from the ECM connector terminal HFP+ to the fuel pump (high pressure).
  • The voltage is grounded to the ECM connector terminal HFP- from the fuel pump (high pressure).
 
 
TECHNICAL DESCRIPTION
In response to the signal from the ECM, the fuel pump (high pressure) controls fuel pressure.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • The ECM detects short malfunction.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • Battery positive voltage is between 10 and 16.5 volts.
  • More than 2 seconds have passed since the engine starting sequence was completed.
  • Power supply voltage for injector (high pressure) driver is more than 10 volts.
Judgment Criterion
  • A malfunction by ground fault occurred for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • While prohibiting the operation of the injector (high pressure), carry out the control by the injector operation only.
  • Torque is restricted.
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
  • Fuel pump (high pressure) failed.
  • Shorted fuel pump (high pressure) circuit, harness damage or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Check the fuel pump (high pressure).
Refer to Fuel Pump (high pressure) Check .
Is the measured resistance normal?
Go to Step 2.
Replace the fuel pump (high pressure). Then go to Step 5.
 
STEP 2. Check of short circuit to ground and harness damage in HFP+ line between fuel pump (high pressure) connector and ECM connector.
Is the harness wire in good condition?
Go to Step 3.
Repair the connector(s) or wiring harness. Then go to Step 5.
 
STEP 3. Check of short circuit to ground and harness damage in HFP- line between fuel pump (high pressure) connector and ECM connector.
Is the harness wire in good condition?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 5.
 
STEP 4. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0628 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 5.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 5. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0628 set?
Retry the troubleshooting.
The inspection is complete.