DTC Troubleshooting: P0301 (71), P0302 (72), P0303 (73), P0304 (74)
  1. At injector side, measure resistance between injector 2P connector terminals No. 1 and No. 2.
Is there 10−13 Ω?
YES -
Go to Step 55 .
NO -
Replace the injector, then go to Step 60 .
  1. Substitute a known-good injector from the problem cylinder.
  1. Reconnect all connectors.
  1. Start the engine, and let it idle for 2 minutes.
  1. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VSS
    • REL TP SENSOR
    • CLV (calculated load value)
    • APP SENSOR
  1. Check the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, and/or CYL4 MISFIRE in the DATA LIST for 10 minutes with the HDS.
Does the CYL1 MISFIRE, CYL2 MISFIRE, CYL3 MISFIRE, and/or CYL4 MISFIRE show misfire counts?
YES -
Go to Step 70 .
NO -
Replace the original injector, then go to Step 60 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Clear the CKP pattern with the HDS.
  1. Do the ECM idle learn procedure.
  1. Do the CKP pattern learn procedure.
  1. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VSS
    • REL TP SENSOR
    • CLV (calculated load value)
    • APP SENSOR
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0301, P0302, P0303, or P0304 indicated?
YES -
Check for poor connections or loose terminals at the ignition coil, the injector, and the ECM, then go to troubleshooting DTC P0300, P0301, P0302, P0303 or P0304.
NO -
Go to Step 69 .
  1. Monitor the OBD STATUS for DTC P0301, P0302, P0303, or P0304 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in Step 68 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the ignition coil, the injector, and the ECM, then go to Step 1 . If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to Step 67 .
  1. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
  1. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VSS
    • REL TP SENSOR
    • CLV (calculated load value)
    • APP SENSOR
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0301, P0302, P0303, or P0304 indicated?
YES -
Check for poor connections or loose terminals at the ignition coil, the injector, and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 71 . If the ECM was substituted, go to Step 1 .
NO -
Go to Step 73 .
  1. Monitor the OBD STATUS for DTC P0301, P0302, P0303, or P0304 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs were indicated in Step 72 , go to the indicated DTC's troubleshooting.■
NO -
If the screen indicates FAILED, check for poor connections or loose terminals at the ignition coil, the injector, and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 71 . If the ECM was substituted, go to Step 1 . If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to Step 71 .