[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. P21DB NO.1 INJECTOR CIRCUIT LOW INPUT (DIRECT INJECTION)
Code No. P21DB: No. 1 Injector Circuit Low Input (Direct 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.
 
 
OPERATION
  • Power is supplied to the No. 1 injector (high pressure) from the engine-ECU connector terminal DI+1.
  • The engine-ECU connector terminal DI-1 makes the power transistor in the unit be in ON position, and that makes currents go on the No. 1 injector (high pressure).
 
 
FUNCTION
  • The engine-ECU 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.
 
 
TROUBLE JUDGEMENT
Check Conditions
  • After 2 seconds since the ignition switch is turned ON or since the completion of engine start.
  • Battery positive voltage is more than 10 V and is less than 16.5 V.
  • Power supply voltage for injector (high pressure) driver is more than 10 V.
Judgement Criterion
  • A malfunction by open circuit/short to earth 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.
 
 
PROBABLE CAUSES
  • Failed No. 1 injector (high pressure)
  • Open/short circuit or harness damage in No. 1 injector (high pressure) circuit or loose connector contact
  • Failed engine-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. Perform resistance measurement at injector (high pressure) intermediate connector.
  • Disconnect connector, and measure at No. 1 injector (high pressure) side.
  • Resistance between engine-ECU DI+1 line and DI-1 line.
OK: 1.74 - 2.04 Ω (at 20°C)
Is the check result normal?
Go to Step 5.
Go to Step 2.
 
STEP 2. Check of open circuit, and damage in DI+1 line between injector (high pressure) intermediate connector and No. 1 injector (high pressure) connector.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check of open circuit, and damage in DI-1 line between injector (high pressure) intermediate connector and No. 1 injector (high pressure) connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Check No. 1 injector (high pressure) itself.
  • No. 1 injector (high pressure) check (Refer to ).
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the No. 1 injector (high pressure).
 
STEP 5. Check of short to earth in DI+1 line between injector (high pressure) intermediate connector and No. 1 injector (high pressure) connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of short to earth in DI-1 line between injector (high pressure) intermediate connector and No. 1 injector (high pressure) connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Check of open circuit, and damage in DI+1 line between injector (high pressure) intermediate connector and engine-ECU connector.
Is the check result normal?
Go to Step 8.
Repair the connector(s) or wiring harness.
 
STEP 8. Check of short to earth, open circuit, and damage in DI-1 line between injector (high pressure) intermediate connector and engine-ECU connector.
Is the check result normal?
Go to Step 9.
Repair the connector(s) or wiring harness.
 
STEP 9. M.U.T.-IIISE diagnosis code
  • Reconfirmation of diagnosis code.
Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).