LEMON Manuals: Even more car manuals for everyone
Home >> Dodge and Ram >> 2003 >> Durango Base, 5.9 Z, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (Engine Controls - Self-Diagnostics - 3.9L & 5.9L) >> Diagnostic Tests >> DTC P1398: Mis-Fire Adaptive Numerator At Limit >> Testing

DTC P1398: Mis-Fire Adaptive Numerator At Limit: Testing

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Check for any Technical Service Bulletin (TSB) that may apply to this DTC.
  1. With the DRBIII(R) scan tool, read the DTCs and record the related freeze frame data. Use this information to help duplicate the conditions that set the DTC. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load. Turn ignition on, with engine off. With the DRBIII(R) scan tool in the Misc Menu, select Clear PCM (battery disconnect) to reset the PCM. With the DRBIII(R) scan tool, select the Misfire Pretest screen. Road test the vehicle and relearn the adaptive numerator. The adaptive numerator is learned when the Adaptive Numerator Done Learning line on the Misfire screen changes to Yes. Did the adaptive numerator relearn? If yes, see INTERMITTENT CONDITION  under SELF-DIAGNOSTIC SYSTEM. If no, go to next step.
    2. NOTE: Check for any Technical Service Bulletin (TSB) that may apply to this DTC.
  2. Turn the ignition off. Visually inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals. Visually inspect the related wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Ensure the CMP sensor is tight. Were any problems found? If yes, repair as necessary. If no, go to next step.
  3. Visually inspect the CKP sensor and related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals. Visually inspect the related wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Ensure the CKP sensor mounting bolt(s) are tight. Were any problems found? If yes, repair as necessary. If no, go to next step.
  4. Disconnect and remove the CKP sensor. Inspect the tone wheel/flexplate slots for damage, foreign material, or excessive movement. Is the tone wheel/flexplate free from defects? If yes, go to next step. If no, repair/replace tone wheel/flex plate as necessary.
    5. WARNING: When the engine is operating, DO NOT stand in a direct line with the fan. DO NOT put your hands near the pulleys, belts or fan. DO NOT wear loose clothing.
  5. With the DRBIII(R) lab scope probe and the Miller Special Tool (6801), backprobe the CKP sensor signal circuit in the PCM harness connector. Start the engine and observe the lab scope screen for any erratic CKP sensor pulses. Were any erratic CKP sensor signals detected? If yes, replace the CKP sensor. If no, go to next step. Turn the ignition off before continuing.
    6. NOTE: Before continuing, disconnect the PCM harness connectors and check the related wiring terminals for corrosion, damage or terminal push out. Repair as necessary.
  6. Using the wiring diagram as a guide, inspect the wire harness and connectors. Visually inspect the related wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect both the component and the PCM connectors. Pay particular attention to all power and ground circuits. If there are no possible causes remaining, replace and program the PCM. See PROGRAMMING  .
scientia non olet · About LEMON Manuals