Engine Control System: Diagnosis Hyundai Accent III

ECM Problem Inspection Procedure

1. TEST ECM GROUND CIRCUIT: Measure resistance between ECM and chassis ground using the backside of ECM harness connector as ECM side check point. If the problem is found, repair it. Specification: below 1ohms
2. TEST ECM CONNECTOR: Disconnect the ECM connector and visually check the ground terminals on ECM side and harness side for bent pins or poor contact pressure. If the problem is found, repair it.
3. If problem is not found in Step 1 and 2, the ECM could be faulty. If so, replace the ECM with a new one, and then check the vehicle again. If the vehicle operates normally then the problem was likely with the ECM.
4. RE-TEST THE ORIGINAL ECM : Install the original ECM (may be broken) into a known-good vehicle and check the vehicle. If the problem occurs again, replace the original ECM with a new one. If problem does not occur, this is intermittent problem (Refer to Intermittent Problem Procedure in «BASIC INSPECTION PROCEDURE»(ref-380272-S14853803452010121800000) )

Inspection

1. Connect a scan tool on Data Link Connector (DLC).
2. Check MAPS output voltage at idle and IG ON. MANIFOLD ABSOLUTE PRESSURE SENSOR OUTPUT VOLTAGE CHART Condition Output Voltage (V) IG ON 3.9 ~ 4.1 Idle 0.8 ~ 1.6

1. Turn ignition switch OFF.
2. Disconnect IATS connector.
3. Measure resistance between IATS terminals 3 and 4.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S30694089892010121800000) "

1. Turn ignition switch OFF.
2. Disconnect ECTS connector.
3. Remove the ECTS.
4. After immersing the thermistor of the sensor into engine coolant, measure resistance between ECTS terminals 1 and 3.
5. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S14206168072010121800000) "

1. Connect a scan tool on the Data Link Connector (DLC).
2. Start engine and check output voltages of TPS at C.T and W.O.T. Specification: Refer to " «SPECIFICATION»(ref-380273-S19785987802010121800000) "
3. Turn ignition switch OFF and disconnect the scan tool from the DLC.
4. Disconnect TPS connector and measure resistance between TPS terminals 2 and 3. Specification: Refer to " «SPECIFICATION»(ref-380273-S19785987802010121800000) "

1. Check signal waveform of CKPS and CMPS using a scan tool. Specification: Refer to " «WAVEFORM»(ref-380273-S07947398492010121800000) "

1. Check signal waveform of CKPS and CMPS using a scan tool. Specification: Refer to " «WAVEFORM»(ref-380273-S38223662322010121800000) "

1. Check signal waveform of HO2S using a scan tool. Specification: Refer to " «WAVEFORM»(ref-380273-S06410376692010121800000) "
2. Disconnect the HO2S connector.
3. Measure resistance between HO2S heater terminals 3 and 4.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S23413338462010121800000) "

1. Connect a scan tool on the Data Link Connector (DLC).
2. Measure the output voltage of the FTPS. Specification: Refer to " «SPECIFICATION»(ref-380273-S13290550332010121800000) "

1. Turn ignition switch OFF.
2. Disconnect injector connector.
3. Measure resistance between injector terminals 1 and 2.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S04327674142010121800000) "

1. Turn ignition switch OFF.
2. Disconnect ISCA connector.
3. Measure resistance between ISCA terminals 2 and 1 [Opening Coil].
4. Measure resistance between ISCA terminals 2 and 3 [Closing Coil].
5. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S41384404392010121800000) "

1. Turn ignition switch OFF.
2. Disconnect PCSV connector.
3. Measure resistance between PCSV terminals 1 and 2.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S02785383352010121800000) "

1. Turn ignition switch OFF.
2. Disconnect OCV connector.
3. Measure resistance between OCV terminals 1 and 2.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S00280238872010121800000) "

1. Turn the ignition switch OFF.
2. Disconnect the CCV connector.
3. Measure resistance between the CCV terminal 1 and 2.
4. Check that the resistance is within the specification. Specification: Refer to " «SPECIFICATION»(ref-380273-S37327176142010121800000) "
5. Disconnect the vapor hose connected with the canister from the CCV.
6. Connect a vacuum pump to the nipple.
7. Ground the CCV control line and apply battery voltage to the CCV power supply line.
8. Apply vacuum and check the valve operation. Specification: Vacuum maintained