DTC P1201-P1206 Or DTC P1301-P1306: Misfire Detected

NOTE: Trouble shoot DTC P0171, P0172, P0174, P0175, P0335, P0336, P0401, P1128, P1129, P1316, P1317, P1318, P1319, P1336, P1337, P1381, P1382, P1386, P1387, P1491 or P1498, if set, before proceeding.

DTC P1201 or P1301 indicates a misfire in cylinder No. 1 detected. DTC P1202 or P1302 indicates a misfire in cylinder No. 2 detected. DTC P1203 or P1303 indicates a misfire in cylinder No. 3 detected. DTC P1204 or P1304 indicates a misfire in cylinder No. 4 detected. DTC P1205 or P1305 indicates a misfire in cylinder No. 5 detected. DTC P1206 or P1306 indicates a misfire in cylinder No. 6 detected.
If a cylinder misfire DTC is set, check for:
- A fuel injector that is clogged, leaking fuel or air.
- An open or shorted fuel injector circuit.
- An injector resistor malfunction.
- A spark plug carbon deposits, fouling or other malfunction.
- An ignition coil malfunction.
- An Ignition Control Module (ICM) malfunction.
- Low engine compression.
Repair as necessary. If no problems are found, go to next step.
Check for freeze frame data. Perform PCM reset procedure, and clear freeze frame data (if present) and DTC(s). See PCM RESET PROCEDURE/CLEARING CODES . Install SCS Service Check Connector Tool (07PAZ-0010100). Test drive vehicle several times within range of freeze frame data. If there is no freeze frame data of misfiring, test drive vehicle under various conditions and try to duplicate malfunction. If any misfire DTCs reset, go to next step. If misfire DTCs do not reset, problem is intermittent. System is okay at this time. Check for spark plug fouling (firing is okay at this time).
Exchange spark plug from suspect cylinder with spark plug from another cylinder. Test drive vehicle several times within range of freeze frame data. If misfire occurs in cylinder spark plug was moved to, replace spark plug(s). If misfire still occurs in suspect cylinder, go to next step.
Exchange ignition coil from suspect cylinder with ignition coil from another cylinder. Test drive vehicle several times within range of freeze data. If misfire DTC does not reset, problem is intermittent. Check for an intermittent bad contact in ignition coil connector from suspect cylinder (firing is okay at this time). If DTC indicates a misfire in cylinder that coil was moved to, replace faulty ignition coil. If misfire still occurs in suspect cylinder, go to next step.
Start engine. Listen for clicking sound at each fuel injector. If clicking occurs at each injector, go to next step. If an injector is not clicking, check for shorts or open in wiring harness between injector and PCM, and between injector and injector resistor. Repair as necessary. If wiring is okay, replace injector and retest. If problem still exists, substitute a known-good PCM, then recheck. If symptom or indication goes away, replace original PCM.
Exchange fuel injector from suspect cylinder with injector from another cylinder. Allow engine to idle for 2 minutes. Test drive vehicle several times within range of freeze frame data. If there is no freeze frame data of misfiring, test drive vehicle under various conditions and try to duplicate malfunction. If any misfire DTC resets, go to next step. If no misfire DTCs reset, problem is intermittent. Check for a bad contact in injector connector from suspect cylinder (firing is okay at this time).
If misfire occurs in cylinder fuel injector was moved to, replace faulty fuel injector. If misfire is still detected in suspect cylinder, check ignition system wiring harness between PCM and ICM, ignition coil and ICM, ignition coil and battery, and between ignition coil and spark plug voltage detection module. See WIRING DIAGRAMS article. Repair open(s) or short(s) as necessary. If ignition system wiring harness is okay, go to next step.
Substitute a known-good ICM, then recheck. If misfire is not detected, replace original ICM. If misfire is detected, check cylinder leak-down and compression. See ON-VEHICLE ADJUSTMENTS article.