P0301
DTC P0301: No.1 Cylinder MisfireDTC P0302: No.2 Cylinder Misfire
DTC P0303: No.3 Cylinder Misfire
DTC P0304: No.4 Cylinder Misfire
Special Tools Required
Terminal inspection feeler tool set 07XAJ-001000A
1. After checking and recording the freeze data, reset the ECM/PCM. If there is no freeze data of the misfire, just clear the DTC.
2. Start the engine, and listen for a clicking sound at the injector of the problem cylinder.
Does it click?
YES - Go to step 3.
NO - Go to step 30.
3. Turn the ignition switch OFF, and reset the ECM/PCM.
4. Exchange the ignition coil from the problem cylinder with one from another cylinder.
5. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
6. Check the DTC or the Temporary DTC with the scan tool.
Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated?
YES - Go to step 7.
NO - Intermittent misfire due to poor contact at the ignition coil connector (no misfire at this time). Check the terminal fit at each coil connector with the terminal inspection feeler tool set, TIN 07XAJ-001000A.
7. Determine which cylinder(s) had the misfire.
Does the misfire occur in the cylinder where the ignition coil was exchanged?
YES - Replace the faulty ignition coil.
NO - Go to step 8.
8. Turn the ignition switch OFF, and reset the ECM/PCM.
9. Exchange the spark plug from the problem cylinder with one from another cylinder.
10. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
11. Check the DTC or the Temporary DTC with the scan Tool.
Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated?
YES - Go to step 12.
NO - Intermittent misfire due to spark plug fouling (no misfire at this time).
12. Determine which cylinder(s) had the misfire.
Does the misfire occur in the cylinder where the spark plug was exchanged?
YES - Replace the faulty spark plug.
NO - Go to step 13.
13. Turn the ignition switch OFF, and reset the ECM/PCM.
14. Exchange the injector from the problem cylinder with one from the another cylinder.
15. Let the engine idle for 2 minutes.
16. Test-drive the vehicle several limes in the range of the freeze data or under various conditions if there was no freeze data.
17. Check the DTC or the Temporary DTC with the scan Tool.
Is DTC or Temporary DTC P0301, P0302, P0303 or P0304 indicated?
YES - Go to step 18.
NO - Intermittent misfire due to bad contact at the injector connector (no misfire at this time). Check the terminal fit at each injector with the terminal inspection feeler tool set, TIN 07XAJ-001000A.
18. Determine which cylinder(s) had the misfire.
Does the misfire occur in the cylinder where the injector was exchanged?
YES - Replace the faulty injector.
NO - Go to step 19.
19. Turn the ignition switch OFF.
20. Disconnect the ignition coil 3P connector from the problem cylinder.
21. Turn the ignition switch ON (II).
22. Measure voltage between the ignition coil 3P connector terminal No.3 and body ground.
Is there battery voltage?
YES - Go to step 23.
NO - Repair open or short in the wire between the No.1 IGN COIL (15 A) fuse and the ignition coil.
23. Turn the ignition switch OFF.
24. Check for continuity between the ignition coil 3P connector terminal No.2 and body ground.
Is there continuity?
YES - Go to step 25.
NO - Repair open in the wire between the ignition coil and G101.
25. Disconnect ECM/PCM connector A (31P).
26. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there continuity?
YES - Repair short in the wire between the ECM/PCM and the ignition coil.
NO - Go to step 27.
27. Connect the appropriate ignition coil 3P connector terminal No.1 and body ground with a jumper wire (see table).
28. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the ECM/PCM and the ignition coil.
29. Do an engine compression and a cylinder leakdown test.
Did the engine pass bath tests?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Repair the engine.
30. Disconnect ECM/PCM connector B (24P).
31. Turn the ignition switch ON (II).
32. Measure voltage between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there battery voltage?
YES - Go to step 33.
NO - Go to step 42.
33. Turn the ignition switch OFF.
34. Disconnect the injector 2P connector from the problem cylinder.
35. Measure the resistance between the injector 2P connector terminals No.1 and No.2.
Is there 10 Ohm - 13 Ohm?
YES - Go to step 36.
NO - Replace the injector.
36. Exchange the injector from the problem cylinder with one from another cylinder.
37. Reset the ECM/PCM.
38. Let the engine idle for 2 minutes.
39. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
40. Check the DTC or the Temporary DTC with a scan tool.
Is DTC or Temporary DTC P0301, P0302, P0303, or P0304 indicated?
YES - Go to step 41.
NO - Intermittent misfire due to injector malfunction. Check the terminal fit at each injector with the terminal inspection feeler tool set, T/N 07XAJ-001000A.
41. Determine which cylinder (S) had the misfire.
Does the misfire occur in the cylinder where the injector was exchanged?
YES - Replace the faulty injector.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
42. Turn the ignition switch OFF.
43. Disconnect the injector 2P connector from the problem cylinder.
44. Turn the ignition switch ON (II).
45. Measure voltage between the injector 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 46.
NO Repair open in the wire between the injector and the PGM-FI main relay.
46. Turn the ignition switch OFF.
47. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there continuity?
YES - Repair short in the wire between the ECM/PCM and the injector.
NO - Go to step 48.
48. Connect the appropriate injector 2P connector terminal No.2 to body ground with a jumper wire (see table).
49. Check for continuity between body ground and the appropriate ECM/PCM connector terminal (see table).
Is there continuity?
YES - Replace the injector, then recheck.
NO - Repair open in the wire between the ECM/PCM and the injector.