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Engine Controls - Tests W/codes - 2.3L: Diagnosis Mazda Millenia I

Testing & Diagnostics ~10504 words

SELF-DIAGNOSTIC SYSTEM

Note. New Generation Star (NGS) tester will be referred to as scan tool in following procedures.

VISUAL INSPECTION

Most driveability problems in 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.

Diagnosis & Repair Procedure

  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure and record voltage between ground and terminal No. 3E.
  2. Start and idle engine. Measure and record voltage. Voltage with ignition on should be 1.3-1.5 volts, and 1.5-3.0 volts with engine idling. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect MAF sensor connector. Turn ignition on. Measure voltage between ground and terminal "C" on harness connector. If battery voltage is present, go to next step. If battery voltage is not present, check for open or short circuit between MAF sensor and ECM. Repair as needed.
  4. Check continuity of Black/Blue wire between terminal "A" on MAF harness connector and terminal No. 4D on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Check continuity of Brown wire between terminal "B" on MAF sensor harness connector and terminal No. 3E on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  6. Inspect MAF sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If MAF sensor is okay, go to next step.
  7. Inspect Throttle Position (TP) sensor output voltage. See DTC P0120. Repair or replace as needed. If TP sensor output voltage is okay, go to next step.
  8. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure and record voltage between ground and terminal No. 3U.
  2. Start and run engine at 2000 RPM. Measure and record voltage. Voltage with ignition on should be 2.5-2.8 volts, and 1.5-1.8 volts with engine at 2000 RPM. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect MAP sensor connector. Turn ignition on. Measure voltage between ground and terminal "C" on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between MAP sensor and ECM. Repair as needed.
  4. Check continuity of Black/Yellow wire between terminal "A" on MAP sensor harness connector and terminal No. 3AB on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect MAP sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If MAP sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTICS SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3V.
  2. Voltage should be about 3 volts with intake air temperature of 68° F (20° C). If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect IAT sensor connector. Turn ignition on. Measure voltage between ground and terminal "A" on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between IAT sensor and ECM. Repair as needed.
  4. Check continuity of Black/Yellow wire between terminal "B" on IAT harness connector and terminal No. 3AB on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect IAT sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If IAT sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3Q.
  2. Voltage should be 3.0-3.1 volts with coolant temperature of 68° F (20° C), and .8 volt with engine at normal operating temperature. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect ECT sensor connector. Turn ignition on. Measure voltage between ground and terminal "A" (Red/Green wire) on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between ECT sensor and ECM. Repair as needed.
  4. Check continuity of Black/Yellow wire between terminal "B" on ECT sensor harness connector and terminal No. 3AB on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect ECT sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If ECT sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3B.
  2. Turn ignition on. Slowly depress accelerator pedal to wide open throttle. Voltage should increase evenly as throttle opening is increased. If TP sensor voltage changes as specified, go to step 6). If TP sensor voltage does not change as specified, go to next step.
  3. Turn ignition off. Disconnect TP sensor connector. Turn ignition on. Measure voltage between ground and terminal "A" on TP sensor harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between TP sensor and ECM. Repair as needed.
  4. Check continuity of Black/Yellow wire between terminal "D" on TP sensor harness connector and terminal No. 3AB on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Check continuity of Yellow wire between terminal "B" on TP sensor harness connector and terminal No. 3B on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  6. Inspect MAF sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If MAP sensor is okay, go to next step.
  7. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect cooling fan system. See appropriate ENGINE COOLING FANS section. Repair as needed. If cooling fan system is okay, go to next step.
  2. Inspect ECT sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If ECT sensor is okay, go to next step.
  3. Inspect engine cooling system. Repair as needed. If cooling system is okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent system malfunction may have caused DTC to originally set.
  1. Inspect right front oxygen sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If right front oxygen sensor is okay, go to next step.
  2. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3I.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect right front oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "A" on right front oxygen sensor harness connector and terminal No. 3I on ECM connector. If continuity does not exist, repair Red wire. If continuity exists, go to next step.
  4. Inspect fuel injectors, mass air flow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace right front heated oxygen sensor.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4E.
  2. Voltage should be less than one volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect right front oxygen sensor harness connector. Turn ignition on. Measure voltage between ground and terminal "C" on front oxygen sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Black/White wire between right front sensor and main relay.
  4. Turn ignition off. Check continuity between terminal "B" on right front oxygen sensor harness connector and terminal No. 4E on ECM connector. If continuity does not exist, repair Brown wire. If continuity exists, go to next step.
  5. Check continuity between terminals "B" and "C" on right front oxygen sensor component connector. If continuity exists, go to next step. If continuity does not exist, replace right front oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3D.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect right rear oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "B" on right rearb oxygen sensor harness connector and terminal No. 3AB on ECM connector. If continuity does not exist, repair Black/Yellow wire. If continuity exists, go to next step.
  4. Check continuity between terminal "A" on right rear oxygen sensor harness connector and terminal No. 3D on ECM connector. If continuity does not exist, repair White wire. If continuity exists, go to next step.
  5. Inspect fuel injectors, mass air flow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace right rear heated oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3C.
  2. Voltage should be less than one volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect right rear heated oxygen sensor harness connector. Turn ignition on. Measure voltage between ground and terminal "C" on right rear oxygen sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair White wire between sensor and main relay.
  4. Turn ignition off. Check continuity between terminal "D" on right rear oxygen sensor harness connector and terminal No. 3C on ECM connector. If continuity does not exist, repair Black/Red wire. If continuity exists, go to next step.
  5. Check continuity between terminals "C" and "D" on right rear oxygen sensor component connector. If continuity exists, go to next step. If continuity does not exist, replace right rear oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect left front oxygen sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If left front oxygen sensor is okay, go to next step.
  2. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3M.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect left front oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "A" on left front oxygen sensor harness connector and terminal No. 3M on ECM connector. If continuity does not exist, repair Yellow wire. If continuity exists, go to next step.
  4. Inspect fuel injectors, mass air flow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace left front heated oxygen sensor.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4I.
  2. Voltage should be less than one volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect left front oxygen sensor harness connector. Turn ignition on. Measure voltage between ground and terminal "C" on left front oxygen sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between sensor and main relay.
  4. Turn ignition off. Check continuity between terminal "B" on left front oxygen sensor harness connector and terminal No. 4I on ECM connector. If continuity does not exist, repair White/Blue wire. If continuity exists, go to next step.
  5. Check continuity between terminals "B" and "C" on left front oxygen sensor component connector. If continuity exists, go to next step. If continuity does not exist, replace left front oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in rear of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3H.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect left rear heated oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "A" on left rear oxygen sensor harness connector and terminal No. 3H on ECM connector. If continuity does not exist, repair Green wire. If continuity exists, go to next step.
  4. Check continuity between terminal "B" on left rear oxygen sensor harness connector and terminal No. 3AB on ECM connector. If continuity does not exist, repair Black/Yellow wire. If continuity exists, go to next step.
  5. Inspect fuel injectors, mass air flow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace left rear heated oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in rear of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3G.
  2. Voltage should be less than one volt with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect left rear oxygen sensor harness connector. Turn ignition on. Measure voltage between ground and terminal "C" on left rear oxygen sensor harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between left rear oxygen sensor and main relay.
  4. Turn ignition off. Check continuity between terminal "D" on left rear oxygen sensor harness connector and terminal No. 3G on ECM connector. If continuity does not exist, repair Black/Blue wire. If continuity exists, go to next step.
  5. Check continuity between terminals "C" and "D" on left rear oxygen sensor component connector. If continuity exists, go to next step. If continuity does not exist, replace left rear oxygen sensor.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect intake air system components for air leakage. Repair as needed. If system is okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the following components. Check right front oxygen sensor, fuel injector, ECT sensor, MAF sensor, Throttle Position (TP) sensor, closed throttle position switch, IAT sensor, EGR boost sensor, purge solenoid valve and PCV valve. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check fuel line pressure, fuel pump maximum pressure and pressure regulator. Repair or replace any components as necessary. If all components are okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect intake air system components for air leakage. Repair as needed. If system is okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the following components. Check left front oxygen sensor, fuel injector, ECT sensor, MAF sensor, Throttle Position (TP) sensor, closed throttle position switch, IAT sensor, EGR boost sensor, purge solenoid valve and PCV valve. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check fuel line pressure, fuel pump maximum pressure and pressure regulator. Repair or replace any components as necessary. If all components are okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system, CKP sensor air gap, fuel system and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 1 cylinder), CKP sensor air gap, fuel system (No. 1 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 2 cylinder), CKP sensor air gap, fuel system (No. 2 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 3 cylinder), CKP sensor air gap, fuel system (No. 3 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 4 cylinder), CKP sensor air gap, fuel system (No. 4 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 5 cylinder), CKP sensor air gap, fuel system (No. 5 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Refer to appropriate «BASIC TESTING - 2.3L»(ref-18720) article and inspect the following components. Check ignition system (No. 6 cylinder), CKP sensor air gap, fuel system (No. 6 injector) and engine compression. Repair or replace any components as necessary. If all components are okay, go to next step.
  2. Refer to appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article and inspect the EGR system. Repair or replace any components as necessary. If all components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable connections. Repair as needed. Disconnect knock sensor harness connector. Check continuity between terminal "A" of knock sensor and terminal No. 3S on ECM. If continuity does not exist, repair Red wire. If continuity exists, go to next step.
  2. Check knock sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If knock sensor is okay, go to next step.
  3. Erase DTCs. See CLEARING CODES in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Ensure ignition is off. Check continuity between terminal "B" on CKP sensor harness connector and terminal No. 4AL on ECM connector. If continuity does not exist, repair Blue wire. If continuity exists, go to next step.
  2. Check continuity between terminal "A" on CKP sensor harness connector and terminal No. 4AH on ECM connector. If continuity does not exist, repair Green wire. If continuity exists, go to next step.
  3. Check CKP sensor air gap. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Adjust as needed. If air gap as needed, go to next step.
  4. Check CKP sensor. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. If CKP sensor is okay, go to next step.
  5. Erase DTCs. See CLEARING CODES in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Determine if any other EGR or MAP related DTCs are present. Diagnose and repair those DTCs first. If no other EGR related DTCs are present, go to next step.
  2. Inspect the EGR valve position sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If EGR valve position sensor is okay, go to next step.
  3. Inspect all EGR vent and vacuum hoses. Repair or replace as needed. If all hoses are okay, go to next step.
  4. Inspect the Manifold Absolute Pressure (MAP) sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If MAP sensor is okay, go to next step.
  5. Inspect all MAP sensor and solenoid hoses. Repair or replace as needed. If all hoses are okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4G. If battery voltage is present, go to step 4). If battery voltage is not present, go to next step.
  2. Disconnect EGR solenoid valve (vent) harness connector. Turn ignition on. Measure voltage between ground and terminal "A" (Red/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire for open or short.
  3. Inspect EGR solenoid valve. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If EGR solenoid valve is okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.

Inspect right rear oxygen sensor. See appropriate SYSTEM/COMPONENT TESTS - 2.3L article. Replace as needed. If right rear oxygen sensor is okay, replace catalytic converter.

Inspect heated left rear oxygen sensor. See appropriate SYSTEM/COMPONENT TESTS - 2.3L article. Replace as needed. If left rear oxygen sensor is okay, replace catalytic converter.

  1. Inspect evaporative system hoses. Ensure all hoses are free of clogs and do not leak. Repair or replace as needed. If all hoses are in acceptable condition, go to next step.
  2. Verify fuel tank components are correctly installed. Repair or replace as needed. If fuel tank components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Inspect purge solenoid valve. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If purge solenoid valve is okay, go to next step.
  2. Inspect evaporative hose between purge solenoid valve and intake manifold. Repair or replace as needed. If hose is okay, go to next step.
  3. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4O. If battery voltage is present, go to step 6). If battery voltage is not present, go to next step.
  4. Disconnect purge solenoid valve connector. Measure voltage between ground and terminal "A" (Red/Black wire). If battery voltage is present, go to next step. If battery voltage is not present, check for open or short circuit between purge solenoid valve and main relay.
  5. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on purge solenoid valve harness connector and terminal No. 4O on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair White/Black wire.
  6. Check continuity between terminals on purge solenoid valve component connector. If continuity exists, go to next step. If continuity does not exist, replace purge solenoid valve.
  7. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect CDCV. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If CDCV is okay, go to next step.
  2. Inspect hose between CDCV and charcoal canister. Replace as needed. If hose is okay, go to next step.
  3. Inspect drain passage and air filter for clog. Replace as needed. If hose is okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3F.
  2. Voltage should be about 2.5 volts. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Inspect fuel tank pressure sensor and connecting hose for freezing, clogs or breakage. Repair as needed. If sensor and hose are okay, go to next step.
  4. Turn ignition off. Disconnect fuel tank pressure sensor connector. Turn ignition on. Measure voltage between ground and terminal "C" on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between fuel tank pressure sensor and ECM. Repair as needed.
  5. Inspect fuel tank pressure sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If fuel tank pressure sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect evaporative system hoses. Ensure all hoses are free of clogs and do not leak. Repair or replace as needed. If all hoses are in acceptable condition, go to next step.
  2. Verify fuel tank components are correctly installed. Repair or replace as needed. If fuel tank components are okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 1C.
  2. Voltage should be about zero volts or about 5 volts. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Remove instrument cluster. Disconnect ECM harness connectors. Check continuity of Green/Red wire between terminal No. 1C on ECM connector and terminal No. 2K on instrument cluster harness connector. Repair as needed. If continuity exists, go to next step.
  4. With combination removed, measure continuity between terminals No. 2D and 2H on combination meter connector. If continuity exists, go to next step. If continuity does not exist, replace combination meter or circuit board (as applicable).
  5. Inspect VSS. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If VSS is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4M.
  2. Voltage should be about one volt with ignition on or about 11 volts with engine idling at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect IAC valve harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on IAC valve harness connector. If battery voltage is present, go to next step. If battery voltage is not present, check for open or short in Red/Black wire between IAC valve and main relay.
  4. Turn ignition off. Disconnect ECM harness connectors. Check continuity of Blue/Black wire between terminal No. 4M on ECM connector and terminal "B" on IAC valve harness connector. Repair as needed. If continuity exists, go to next step.
  5. Check continuity between component terminals on IAC valve. If continuity exists, go to next step. If continuity does not exist, replace IAC valve.
  6. Inspect IAC valve. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If IAC valve is okay, go to next step.
  7. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3X.
  2. Voltage should be less than one volt with accelerator released, or battery voltage with accelerator pedal depressed. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect ECM harness connectors. Check continuity of Black/Yellow wire between terminal No. 3AB on ECM connector and terminal "D" on TP sensor harness connector. Repair as needed. If continuity exists, go to next step.
  4. Check continuity of Brown wire between terminal No. 3X on ECM connector and terminal "C" on TP sensor harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect closed throttle position switch portion of throttle position sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace TP sensor as needed. If TP sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 1O.
  2. Voltage should be less than one volt with brake pedal released, or battery voltage with brake pedal depressed. If voltage is within specification, go to step 4). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect ECM harness connectors. Check continuity of White/Green wire between terminal No. 1O on ECM connector and brake switch terminal. Repair as needed. If continuity exists, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2C.
  2. Voltage should be about 3 volts with intake air temperature at 68°F (20°C). If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect IAT (D/C) sensor connector. Turn ignition on. Measure voltage between ground and terminal "A" on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between IAT (D/C) sensor and ECM. Repair as needed.
  4. Turn ignition off. Disconnect ECM harness connectors. Check continuity of Black/Yellow wire between terminal No. 3AB on ECM connector and terminal "B" on IAT (D/C) sensor harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect IAT (D/C) sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If IAT (D/C) sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2K.
  2. Voltage should be about 3 volts with intake air temperature at 68°F (20°C). If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect IAT (L/C) sensor connector. Turn ignition on. Measure voltage between ground and terminal "A" on harness connector. If 5 volts is present, go to next step. If 5 volts is not present, check for open or short circuit between IAT (L/C) sensor and ECM. Repair as needed.
  4. Turn ignition off. Disconnect ECM harness connectors. Check continuity of Black/Yellow wire between terminal No. 3AB on ECM connector and terminal "B" on IAT (L/C) sensor harness connector. Repair as needed. If continuity exists, go to next step.
  5. Inspect IAT (L/C) sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If IAT (L/C) sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3I.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect right front oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "A" on right front oxygen sensor harness connector and terminal No. 3I on ECM connector. If continuity does not exist, repair Red wire. If continuity exists, go to next step.
  4. Inspect fuel injectors, mass airflow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace right front heated oxygen sensor.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3M.
  2. Voltage should be 0-1.0 volt with engine idling at normal operating temperature. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect left front oxygen sensor harness connector. Using ohmmeter, backprobe ECM harness connector. Check continuity between terminal "A" on left front oxygen sensor harness connector and terminal No. 3M on ECM connector. If continuity does not exist, repair Yellow wire. If continuity exists, go to next step.
  4. Inspect fuel injectors, mass airflow sensor, engine coolant temperature sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. Inspect fuel pressure regulator. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. Inspect spark plugs and air intake system. Repair or replace as needed. If all items are okay, replace left front heated oxygen sensor.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 1H.
  2. Voltage should be about 10 volts during starting, and less than one volt with engine running. If voltage is within specification, go to step 4). If voltage is not within specification, go to next step.
  3. Disconnect starter harness connector. Disconnect ECM harness connector. Check continuity between terminal "S" on starter harness connector and terminal No. 1H on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Black/Blue wire.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2R.
  2. Voltage should initially be about 1 volt, then battery voltage after about 3 minutes. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect PRC solenoid valve harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on PRC solenoid valve harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on PRC solenoid valve harness connector and terminal No. 2R on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Green/Black wire.
  5. Check continuity between PRC solenoid valve component terminals. If continuity exists, go to next step. If continuity does not exist, replace PRC solenoid valve.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Disconnect distributor connector. Measure voltage between ground and terminal "B". If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire.
  2. Turn ignition is off. Check continuity between terminal "C" on CMP harness connector and terminal No. 4F on ECM connector. If continuity does not exist, repair Blue/Red wire. If continuity exists, go to next step.
  3. Connect CMP connector. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4F.
  4. Voltage should be zero or about 5 volts with ignition on, or about 2.5 volts with engine idling. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  5. Check CMP sensor. See appropriate «BASIC TESTING - 2.3L»(ref-18720) article. Replace as needed. If CMP sensor is okay, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. If all connectors are okay, go to next step.
  2. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable PCM harness connector. Measure voltage between ground and terminal No. 3R. If voltage is about .8 volt, go to step 8). If voltage is not about .8 volt, go to next step.
  3. Disconnect EGR valve position sensor harness connector. Measure voltage between ground and terminal "B". If 5 volts is present, go to next step. If 5 volts is not present, check for open or short in Light Green/Red wire.
  4. Turn ignition off. Disconnect PCM harness connector. Check continuity between terminal "A" on EGR valve position sensor harness connector and terminal No. 3AB on PCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Black/Yellow wire.
  5. Check continuity between terminal "C" on EGR boost sensor harness connector and terminal No. 3R on PCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Red/Black wire.
  6. Inspect EGR valve position sensor. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If EGR valve position sensor is okay, go to next step.
  7. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace PCM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4R. If battery voltage is present, go to step 5). If battery voltage is not present, go to next step.
  2. Disconnect CDCV harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on CDCV harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Black/White wire between solenoid and main relay.
  3. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on CDCV harness connector and terminal No. 4R on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Black/Blue wire.
  4. Check continuity between CDCV component terminals. If continuity exists, go to next step. If continuity does not exist, replace CDCV.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect evaporative system hoses. Ensure all hoses are free of clogs and do not leak. Repair or replace as needed. If all hoses are in acceptable condition, go to next step.
  2. Inspect CDCV. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If CDCV is okay, go to next step.
  3. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 3K.
  2. Voltage should be about 6 volts when fuel tank is full, and 0 volts when tank is low. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect fuel pump connector. Check continuity of Green/Yellow wire between terminal "B" on fuel gauge sending unit harness connector and terminal No. 3K on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  4. Inspect fuel gauge and fuel gauge sending unit. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT section. Repair or replace as needed. If both components are okay, go to next step.
  5. Check continuity of Brown/Red wire between terminal "B" on fuel gauge sending unit harness connector and terminal No. 2N on instrument cluster harness connector. Repair as needed. If continuity exists, go to next step.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vacuum connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4K.
  2. Battery voltage should be present. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect EGR solenoid valve (vacuum) harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on EGR solenoid valve (vacuum) harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on EGR solenoid valve (vacuum) harness connector and terminal No. 4K on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Green/White wire.
  5. Check continuity between EGR solenoid valve (vacuum) component terminals. If continuity exists, go to next step. If continuity does not exist, replace EGR solenoid valve (vacuum).
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vent connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4G.
  2. Battery voltage should be present. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect EGR solenoid valve (vent) harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on EGR solenoid valve (vent) harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on EGR solenoid valve (vent) harness connector and terminal No. 4G on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Green/Black wire.
  5. Check continuity between EGR solenoid valve (vent) component terminals. If continuity exists, go to next step. If continuity does not exist, replace EGR solenoid valve (vent).
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4P.
  2. Battery voltage should be present with engine idling. If voltage is within specification, go to step 5). If voltage is not within specification, go to next step.
  3. Turn ignition off. Disconnect MAP sensor solenoid valve connector. Turn ignition on. Measure voltage between ground and terminal "A" on harness connector. If battery voltage is present, go to next step. If battery is not present, check for open or short circuit between MAP sensor solenoid valve connector and main relay. Repair as needed.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity of White/Green wire between terminal "B" on MAP sensor solenoid valve harness connector and terminal No. 4P on ECM harness connector. Repair as needed. If continuity exists, go to next step.
  5. Check continuity between MAP sensor solenoid valve component terminals. If continuity exists, go to next step. If continuity does not exist, replace MAP sensor solenoid valve.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vent connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 1AA.
  2. Battery voltage should be present with engine at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect by-pass air solenoid valve harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on bypass air solenoid valve harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on by-pass air solenoid valve harness connector and terminal No. 1AA on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair White wire.
  5. Check continuity between by-pass air solenoid valve component terminals. If continuity exists, go to next step. If continuity does not exist, replace by-pass air solenoid valve.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vent connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2E.
  2. Battery voltage should be present with engine at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect charge air cooler by-pass solenoid valve harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on charge air cooler by-pass solenoid valve harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on charge air cooler by-pass solenoid valve harness connector and terminal No. 2E on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Blue/Yellow wire.
  5. Check continuity between charge air cooler by-pass solenoid valve component terminals. If continuity exists, go to next step. If continuity does not exist, replace charge air cooler by-pass solenoid valve.
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vent connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2M.
  2. Battery voltage should be present with engine at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect air by-pass solenoid valve (vacuum) harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on air by-pass solenoid valve (vacuum) harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on air bypass solenoid valve (vacuum) harness connector and terminal No. 2M on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair White/Red wire.
  5. Check continuity between air by-pass solenoid valve (vacuum) component terminals. If continuity exists, go to next step. If continuity does not exist, replace air by-pass solenoid valve (vacuum).
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable electrical harness and vent connections. Repair as needed. Turn ignition on. Access ECM harness connector. ECM is mounted to bulkhead, behind passenger seat. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 2A.
  2. Battery voltage should be present with engine at normal operating temperature. If voltage is within specification, go to step 6). If voltage is not within specification, go to next step.
  3. Disconnect air by-pass solenoid valve (vent) harness connector. Ensure ignition is on. Measure voltage between ground and terminal "A" on air by-pass solenoid valve (vent) harness connector. If battery voltage is present, go to next step. If battery voltage is not present, repair Red/Black wire between solenoid and main relay.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between terminal "B" on air by-pass solenoid valve (vent) harness connector and terminal No. 2A on ECM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Brown/Yellow wire.
  5. Check continuity between air by-pass solenoid valve (vent) component terminals. If continuity exists, go to next step. If continuity does not exist, replace air by-pass solenoid valve (vent).
  6. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Determine if any other DTCs are displayed. Repair those DTCs first. If no other DTCs are displayed, go to next step.
  2. Inspect ABV vent and vacuum solenoid. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If ABV vent and vacuum solenoid are okay, go to next step.
  3. Inspect all applicable system vacuum hoses for clogs or leaks. Repair or replace as needed. If hoses are okay, go to next step.
  4. Inspect ABV actuator. See appropriate «SYSTEM/COMPONENT TESTS - 2.3L»(ref-18676) article. Replace as needed. If ABV actuator is okay, go to next step.
  5. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Access TCM harness connector. TCM is mounted to upper left kick panel, behind instrument panel. Access ECM harness connector. ECM is mounted in front of center console, under radio.
  2. Disconnect ECM and TCM connectors. Using ohmmeter, check continuity between terminal No. 1B on ECM harness connector and terminal No. 2K on TCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Green wire.
  3. Check continuity between terminal No. 1F on ECM harness connector and terminal No. 2N on TCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair White/Red wire.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Inspect all applicable harness connectors. Repair as needed. Ensure ignition is off. Disconnect ECM harness connector. ECM is mounted in front of center console, under radio. Disconnect ABS/TCS control module harness connector. ABS/TCS control module is mounted to upper left kick panel, behind instrument panel, next to TCM.
  2. Check continuity between terminal No. 1Q on ECM harness connector and terminal No. 2S on ABS/TCS control module harness connector. If continuity exists, go to next step. If continuity does not exist, repair Pink/Green wire.
  3. Inspect ABS/TCS control module. See appropriate ANTI-LOCK article in BRAKES section. Replace as needed. If ABS/TCS control module is okay, go to next step.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.
  1. Ensure battery is fully charged and in acceptable condition. Correct as needed. Inspect MAIN fuse. Replace as needed. If main fuse is okay, go to next step.
  2. Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, under radio. Using voltmeter, backprobe applicable ECM harness connector. Measure voltage between ground and terminal No. 4B.
  3. Battery voltage should be present. If voltage is within specification, go to next step. If voltage is not within specification, repair Blue/Red wire between ECM and MAIN fuse.
  4. Erase DTCs. See «CLEARING CODES»(ref-18648-S31699417242000123000000) in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace ECM. If DTC is not present, intermittent poor connection may have caused DTC to orginally set.

More articles — Engine Controls - Tests W/codes - 2.3L