M/T Model
DTC P0304: Cylinder 4 Misfire Detected - M/T ModelNOTE: If some of the DTCs listed below are stored at the same time as a misfire DTC, troubleshoot those DTCs first, the recheck for the misfire DTC.
P0131, P0132: Primary HO2S
P0171, P0172: Fuel supply system
P0335, P0336: CKP Sensor
P0401: EGR system
P0340, P0341, P0365, P0366: CMP (TDC) Sensor A/B
1. After checking and recording the freeze data, reset the ECM. If there is no freeze data of misfiring, just clear the DTC.
2. Exchange the spark plug from the problem cylinder with one from another cylinder.
3. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
4. Check the DTC or the Temporary DTC with scan tool.
Is DTC P0301, P0302, P0303, P0304, P0305, P0306, or Temporary DTC P1399 indicated?
YES - Go to step 5.
NO - Intermittent misfire due to spark plug fouling, etc. (no misfire at this time).
5. 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 6.
6. Remove the ignition coil cover.
7. Exchange the ignition coil from the problem cylinder with one from another cylinder.
8. Let the engine idle for two minutes.
9. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
Is DTC P0301 P0302, P0303, P0304, P0305, P0306, or Temporary DTC P1399 indicated?
YES - Go to step 10.
NO - Intermittent misfire due to ignition coil fouling, etc (no misfire at this time).
10. 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 11.
11. Turn the ignition switch OFF.
12. Disconnect the ignition coil 3P connector from the problem cylinder.
13. Turn the ignition switch ON (II).
14. Measure voltage between ignition coil 3P connector terminal No.3 and body ground.
Is there battery voltage?
YES - Go to step 15.
NO - Repair open or short in the wire between the No.11 IG COIL (15 A) fuse and the ignition coil.
15. Turn the ignition switch OFF.
16. Check for continuity between ignition coil 3P connector terminal No.2 and body ground.
Is there continuity?
YES - Go to step 17.
NO - Repair open in the wire between the ignition coil and G101 (or G102).
17. Disconnect ECM connector B (24P).
18. Check for continuity between body ground and ECM connector terminal(s) (see table).
Is there continuity?
YES - Repair short in the wire between the ECM and the ignition coil.
NO - Go to step 19.
19. Reconnect ECM connector B (24P).
20. Connect ignition coil 3P connector terminal No.1 and body ground with a jumper wire. (see table)
21. Check for continuity between body ground and the ECM connector terminal(s). (see table)
Is there continuity?
YES - Go to step 22.
NO - Repair open in the wire between the ECM and the ignition coil.
22. Disconnect ECM connector B (24P).
23. Turn the ignition switch ON (II).
24. Measure voltage between body ground and the ECM connector terminal(s). (see table)
Is there battery voltage?
YES - Go to step 25.
NO - Go to step 34.
25. Remove the intake manifold.
26. Disconnect the injector 2P connector from the problem cylinder.
27. Measure the resistance between injector 2P connector terminals No. 1 and No. 2.
Is there 10 - 13 Ohms?
YES - Go to step 28.
NO - Replace the injector.
28. Exchange the injector from the problem cylinder with one from another cylinder.
29. Install the intake manifold.
30. Let the engine idle for two minutes.
31. Test-drive the vehicle several times in the range of the freeze data or under various conditions if there was no freeze data.
Is DTC P0301, P0302, P0303, P0304, P0305, P0306, or Temporary DTC P1399 indicated?
YES - Go to step 32.
NO - Intermittent misfire due to injector fouling, etc.
32. Determine which cylinder(s) had the misfire.
Is DTC P0301, P0302, P0303, P0304, P0305, P0306, or Temporary DTC P1399 indicated?
YES - Replace the faulty injector.
NO - Go to step 33.
33. Check the engine compression.
Is the engine compression OK?
YES - Substitute a known-good ECM and recheck. If the symptom/indication goes away, replace the original ECM.
NO - Repair the engine.
34. Turn the ignition switch OFF.
35. Remove the intake manifold.
36. Disconnect the injector 2P connector on the problem cylinder.
37. Turn the ignition switch ON (II).
38. Measure voltage between injector 2P connector terminal No.1 and body ground.
Is there battery voltage?
YES - Go to step 39.
NO - Repair open in the wire between injector and the PGM-FI main relay.
39. Turn the ignition switch OFF.
40. Check for continuity between body ground and the ECM connector terminal(s). (see table)
Is there continuity?
YES - Repair short in the wire between the ECM and the injector.
NO - Go to step 41.
41. Connect injector 2P connector terminal No.2 to body ground with a jumper wire (see table).
42. Check for continuity between body ground and the ECM connector terminals(s) (See table).
Is there continuity?
YES - Replace the injector, then recheck.
NO - Repair open in the wire between the ECM and the injector.