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DTC P21DC: Injector Circuit High Input - Cylinder 1 (direct fuel injection)
 
 
warningSince the injector (high pressure) drive circuit is high voltage and there is a danger of electric shock, do not measure the terminal voltage.
 
 
CIRCUIT OPERATION
  • Power is supplied to the No. 1 cylinder injector (high pressure) from the ECM connector terminal DI+1.
  • The ECM connector terminal DI-1 makes the power transistor in the unit be in ON position, and that makes currents go on the No. 1 cylinder injector (high pressure).
 
 
TECHNICAL DESCRIPTION
  • The ECM controls the power supply interval of the injector (high pressure).
  • The fuel injection amount of the injector (high pressure) depends on the power supply interval.
 
 
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
  • Ignition switch is "ON" position.
  • After 2 seconds pass from the time when the engine is stopped.
  • Battery positive voltage is between 10 and 16.5 volts.
  • Power supply voltage for injector (high pressure) driver is more than 10 volts.
Judgment Criterion
  • A malfunction by short circuit occurred for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
<Malfunction in single cylinder>
  • Prohibit driving the malfunctioning cylinder injector and injector (high pressure).
<Malfunctions in multiple cylinders>
  • 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: )
  • No. 1 cylinder injector (high pressure) failed.
  • Shorted No. 1 cylinder injector (high pressure) circuit, harness damage or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Check of short circuit and harness damage in DI-1 line between No. 1 cylinder injector (high pressure) connector and ECM connector.
Is the harness wire in good condition?
Go to Step 2.
Repair the connector(s) or wiring harness. Then go to Step 5.
 
STEP 2. Check of short circuit in DI+1 line between No. 1 cylinder injector (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 the No. 1 cylinder injector (high pressure).
Refer to No. 1 Cylinder Injector (high pressure) Check .
Is the measured resistance normal?
Go to Step 4.
Replace the No. 1 cylinder injector (high pressure). 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 P21DC 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 P21DC set?
Retry the troubleshooting.
The inspection is complete.