Engine Controls - Self-Diagnostics - 2.4L: Diagnosis Kia Optima I

ON BOARD DIAGNOSTICS-II (OBD-II)

The purpose of Engine Control Module (ECM) OBD-II software is to ensure proper emission system operation for the life of vehicle. OBD-II monitors emissions related components and systems for deterioration and failure. For emission system related failures, ECM will store a Diagnostic Trouble Code (DTC) and command Malfunction Indicator Light (MIL) to illuminate. See MALFUNCTION INDICATOR LIGHT . DTCs can be accessed with Hi-Scan Pro/Kia Data Pro Scan Tool (0K2A1 189 AA0/K96 DP KIT), or equivalent, connected to OBD-II Data Link Connector (OBD-II DLC).

OBD-II software includes advanced diagnostic test modes and allows detection of faults that do NOT illuminate the MIL. Test mode 7 allows verification of repair after one drive cycle. Test mode 7 does not require duplicating particular vehicle operating conditions that existed during original failure. Test mode 22 accesses PIDs (displays component input and output values). Advanced diagnostic test modes can be accessed with Hi-Scan Pro/Kia Data Pro Scan Tool.

DIAGNOSTIC PROCEDURE

Diagnosis of computerized engine control system should be performed in the following order

1. Perform visual inspection. Most driveability problems in the engine control system result from faulty wiring, poor electrical connections or leaking air and vacuum hose connections. To avoid unnecessary component testing, perform a visual inspection before beginning self-diagnostic tests.
2. Ensure all mechanical engine systems other than computerized systems (i.e., compression, ignition, etc.) are operating properly. DO NOT proceed with testing unless all other problems have been repaired. If Malfunction Indicator Light (MIL) is on, see «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-121519-S31808805592001083100000) . For diagnosing DTCs, see appropriate DTC test under «DIAGNOSTIC TESTS»(ref-121519-S25099336252001083100000) .
3. After repairs have been completed, clear DTC(s). See «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-121519-S14250432772001083100000) . Recheck system and verify repair is complete.

RETRIEVING DIAGNOSTIC TROUBLE CODES

Note. To enter self-diagnostics, connect Hi-Scan Pro/Kia Data Pro Scan Tool (0K2A1 189 AA0/K96 DP KIT), or equivalent, to OBD-II Data Link Connector (OBD-II DLC). For specific scan tool operating procedures, see the scan tool manufacturer's instruction manual.

1. Before entering on-board diagnostics, see «SERVICE PRECAUTIONS»(ref-121519-S37183526552001083100000). Turn ignition off. Locate Data Link Connector (OBD-II DLC) under left side of instrument panel and connect scan tool to DLC. (Scheme 57)
2. Start engine and retrieve Diagnostic Trouble Codes (DTCs). Read and record scan tool self-diagnostic output (stored codes). See «DIAGNOSTIC TROUBLE CODE INDEX»(ref-121519-S33342044832001091800000) table. To perform testing for retrieved codes, see appropriate DTC test under «DIAGNOSTIC TESTS»(ref-121519-S25099336252001083100000).

Scheme 57

Scheme 58

CLEARING DIAGNOSTIC TROUBLE CODES

DTCs may be cleared by using scan tool or disconnecting negative battery cable for at least 20 seconds. Clearing DTCs will also clear freeze frame data. Reconnect negative battery cable. verify DTCs have been erased.

DIAGNOSTIC TESTS

Note. For circuit identification, see WIRING DIAGRAMS article.

Note. After all repairs, clear codes. Verify repairs by driving vehicle with Hi-Scan Pro/Kia Data Pro connected to OBD-II Data Link Connector (OBD-II DLC) and monitoring for pending codes.

Note. In some instances a short to ground or a short to power may cause damage to control modules. Do not replace control modules until testing proves these conditions do not exist. Also verify that ground circuits have good continuity to ground.

Diagnostic Aids

Engine Control Module (ECM) continuously monitors input from Mass Airflow (MAF) sensor. ECM will set code if input is more or less than range of expected values for current engine operating conditions.

Check for following possible problems

1. Dirty air cleaner.
2. Oil cap or dipstick missing or improperly installed.
3. Air leak in intake system.
4. Contaminated, deteriorated or damaged MAF sensor.
5. Faulty MAF sensor or Throttle Position (TP) sensor.
6. Faulty wiring between Engine Control Module (ECM) and MAF sensor or TP sensor.

Engine Control Module (ECM) continuously monitors input from MAF sensor. ECM will set code if input is less or more than range of expected values for current engine operating conditions.

Check for following possible problems

1. Open or short to ground between MAF sensor and ECM.
2. Open between MAF sensor and main relay (EGI).
3. Open between MAF sensor and ground.
4. Faulty MAF sensor.

Code will set if at least 60 seconds have passed since engine started, engine is idling and IAT sensor temperature input to Engine Control Module (ECM) is less than -49°F (-45°C) or more than 257°F (125°C). Conditions are continuously monitored.

Check for following possible problems

1. Open or short to power in Tan wire between IAT sensor and ECM.
2. Open in Tan wire between IAT sensor and ECM.
3. Short to ground in Tan wire between IAT sensor and ECM.
4. Short between IAT sensor wires.
5. IAT sensor malfunction.

DTC P0116 will set when difference between calculated temperature and measured temperature is more than range of expected values.

DTC P0125 will set if elapsed time before engine feedback operation is initiated is too long. engine coolant temperature input is insufficient for closed loop operation.

Check for following possible problems

1. ECT sensor malfunction.
2. Poor connections between ECT sensor and Engine Control Module (ECM).

Code will set if closed throttle switch is set to on and input voltage is more than 2 volts for 4 seconds, or voltage is less than 0.2 volts for 4 seconds. Code will set if input voltage is higher than 4.6 volts for 4 seconds.

Check for following possible problems

1. Open or short to ground in wire between TP sensor and Engine Control Module (ECM).
2. Open or short to power in wire between TP sensor and ECM.
3. Short between TP sensor wires.
4. TP sensor malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Short to power in wire between HO2S and Engine Control Module (ECM).
2. Short to ground in wire between HO2S and Engine Control Module (ECM).
3. Open to power in wire between HO2S and Engine Control Module (ECM).
4. Poor connection between HO2S and ECM.
5. Contaminated or deteriorated HO2S.
6. Incorrect HO2S heater resistance.
7. Front or rear HO2S malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Front and rear HO2S connections reversed.
2. Fault in fuel delivery system.
3. Leak in intake system.
4. Leak in exhaust system.
5. HO2S malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. O2 SENSOR fuse (15-amp) blown.
2. Open in wire between front HO2S and ECM.
3. Front HO2S malfunction.

Heater current of front heated oxygen sensor heater has continued to be 0.2-amps or less, or 3.5-amps or more for 6 second. Monitor runs once per trip.

Check for following possible problems

1. O2 SENSOR FUSE (15-amp) blown.
2. Open or short to power in wire between front HO2S and ECM.
3. Front HO2S malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Short in Black/White wire or Tan wire between rear HO2S and ECM.
2. Loose, damaged or corroded rear HO2S harness connector or ECM harness connector terminals (Open circuit).
3. Rear HO2S malfunction.
4. ECM faulty

If calculated catalyst temperature is more than 846°F (452°C), code will set when air/fuel compensation factor (calculated from rear HO2S) is out of predetermined high and low parameters.

Check for following possible problems

1. Front and rear HO2S connections reversed.
2. Fuel delivery system malfunction.
3. Leak in intake system.
4. Leak in exhaust system.
5. Rear HO2S malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. O2 SENSOR fuse (15-amp) blown.
2. Open in Tan wire or Black/White wire between rear HO2S and ECM.
3. Rear HO2S malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. O2 SENSOR fuse (15-amp) blown.
2. Open or short to power in Black wire between rear HO2S and ECM.
3. Rear HO2S malfunction.

Lambda controller block on minimum or maximum limit.

Check for following possible problems

1. Fuel delivery system malfunction.
2. Intake or exhaust system leak.
3. Mass Airflow (MAF) sensor malfunction.
4. Throttle Position (TP) sensor malfunction.

Code will set if emissions relevant misfire rate exceeds allowed misfires, per 1000 crankshaft revolutions. Code will set if catalyst damaging misfire every 200 crankshaft revolutions exceeds predetermined criteria based on load and RPM. Monitor runs continuously. Emissions relevant misfire is two trip fault. Catalyst damaging misfire is one trip fault and will cause Malfunction Indicator Light (MIL) to continuously blink.

Check for following possible problems

1. Vacuum leak in air intake system.
2. Crankshaft Position (CKP) sensor circuit malfunction.
3. CKP sensor malfunction.
4. Ignition circuit malfunction.
5. Faulty ignition coil or plug wire.
6. Spark plug malfunction.
7. Low compression due to blown head gasket, leaking valve or piston ring.
8. Low or high fuel pressure.
9. Fuel injector circuit malfunction.
10. Faulty fuel injector.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short between Ignition Failure (IF) sensor and Engine Control Module (ECM).
2. Open between IF sensor and ignition coil.
3. Open between IF sensor and ground.
4. IF sensor malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short to ground in wire between knock sensor and Engine Control Module (ECM).
2. Knock sensor malfunction.

Code will set if engine is running and no CKP sensor signal is received by ECM.

Check for following possible problems

1. Open or short in wire between CKP sensor and Engine Control Module (ECM).
2. Open or short in wire between CKP sensor and main relay.
3. Short between CKP sensor wires.
4. CKP sensor malfunction.

No Camshaft Position (CMP) sensor signal when CKP sensor is not faulty.

Check for following possible problems

1. Open or short to ground in wire between CMP sensor and Engine Control Module (ECM).
2. Open or short to power in wire between CMP sensor and Engine Control Module (ECM).
3. Short between CMP sensor wires.
4. CMP sensor malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short between ignition coil and ECM.
2. Open in Black/Yellow wire between CMP sensor and ground.
3. Open in Pink/Black wire between IGN COIL fuse (20-amp) and ignition coil.
4. Open or short between ignition coil and spark plug.
5. Short between ignition coil wires.
6. Ignition coil malfunction.

Exhaust gas flow signal changes little when EGR solenoid is turned on. MAP sensor signal is used for detection.

Check for following possible problems

1. EGR valve does not open.
2. EGR control vacuum is too low.
3. EGR solenoid failed.
4. Open or short in EGR solenoid circuit, or loose harness connector.
5. Manifold Absolute Pressure (MAP) sensor failed.
6. ECM failed.

ECM evaluates catalytic converter storage capability by monitoring upstream Heated Oxygen Sensor (HO2S) and downstream HO2S performance, calculating a ratio based on the amplitude of the 2 signals and evaluating this information based on load and speed conditions. Code will set when ECM determines catalytic converter storage capability has degraded.

Check for following possible problems

1. Insufficient engine combustion.
2. Intake system or exhaust system air leak.
3. Improper fuel pressure.
4. Damaged Three Way Catalytic (TWC) converter.

Diagnostic Aid

Code enable criteria not available from manufacturer.

Check for following possible problem. Purge canister solenoid (PSV) valve stuck open.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Fuel filler cap loose or missing.
2. Fuel filler cap "O" ring missing or damaged.
3. Faulty or damaged fuel filler pipe.
4. Leaking, disconnected or plugged fuel vapor lines.
5. Fuel in lines due to faulty rollover valve or On-board Refueling Vapor Recovery (ORVR) valve.
6. Canister Close Valve (CCV) clogged, stuck open or closed.
7. Improperly installed EVAP canister Purge Solenoid Valve ( PSV).
8. PVS valve stuck open or closed.
9. Fuel Tank Pressure Sensor (FTPS) malfunction.
10. Leaking EVAP canister or catch tank.

Code will set if Engine Control Module (ECM) detects Canister Close Valve (CCV) circuit voltage is out of parameters.

Check for following possible problems

1. Open in wire between O2 fuse (15-amp) and CCV.
2. Open in wire between CCV and ECM.
3. Short to ground or short to power in wire between CCV and ECM.
4. CCV malfunction.

Code will set if Engine Control Module (ECM) determines fuel tank pressure exceeds predetermined limit.

Check for following possible problems

1. Short to power in wire between Fuel Tank Pressure Sensor (FTPS) and Engine Control Module (ECM).
2. Short to ground in wire between Fuel Tank Pressure Sensor (FTPS) and Engine Control Module (ECM).
3. High resistance or open in wire between ECM and FTPS.
4. Canister Close Valve (CCV) stuck closed.
5. Blocked vapor hose between EVAP canister and CCV.
6. FTPS malfunction.

Code will set when engine speed is more than 2000 RPM and Engine Control Module (ECM) does not detect Vehicle Speed Sensor (VSS) signal for more than 2.2 milliseconds.

Check for following possible problems

1. Open in Pink wire between B/U Lamp fuse (10-amp) and VSS.
2. Open in Black/White wire between VSS and ground.
3. Open in Brown wire between VSS and ECM.
4. Short to power or short to ground in Brown wire between VSS and ECM.
5. VSS malfunction.
6. Speedometer malfunction.

Code will set when engine is idling, vehicle speed is zero MPH, engine coolant temperature is more than 176°F (80°C) and difference between actual RPM is more than 120 RPM less than desired RPM.

Check for following possible problems

1. High resistance in circuit between IAC valve and Engine Control Module (ECM).
2. IAC valve malfunction.

When engine is idling, vehicle speed is zero MPH and engine coolant temperature is more than 176°F (80°C), code will set if actual RPM is more than 200 RPM greater than desired RPM.

Check for following possible problems

1. Improperly adjusted accelerator cable.
2. Manifold vacuum leak.
3. Faulty PCV valve.
4. Carbon fouled throttle plate.
5. Throttle Position (TP) sensor malfunction.
6. High resistance between IAC valve and Engine Control Module (ECM).
7. IAC valve malfunction.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short between ECM and battery.
2. ECM faulty.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short to ground between MAP sensor and ECM.
2. Open between MAP sensor and ECM.
3. Open between MAP sensor and ground.
4. MAP sensor Faulty.

Code enable criteria not available from manufacturer.

Code enable criteria not available from manufacturer.

Check for following possible problem. Short to ground between ROM change tool and ECM.

Code enable criteria not available from manufacturer.

Check for following possible problems

1. Open or short between ECM and power steering switch.
2. Short to ground between ECM and power steering switch.
3. Power steering switch faulty.