Engine Controls - Tests W/codes: Other Mitsubishi Diamante I

Hard Failures

Hard failures cause Malfunction Indicator Light (MIL) to glow and remain on until malfunction is repaired. If MIL comes on and remains on (MIL may flash) during vehicle operation, cause of malfunction may be determined by using fault codes. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If a sensor fails, ECM will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but loss of good driveability may result.

Intermittent Failures

Intermittent failures may cause Malfunction Indicator Light (MIL) to flicker or glow and go out after intermittent fault goes away. However, corresponding trouble code will be retained in ECM memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECM memory. Intermittent failures may be caused by a sensor, connector or wiring problems. See INTERMITTENTS in TESTS W/O CODES article.

SERVICE PRECAUTIONS

Before proceeding with diagnosis, following precautions must be observed

1. Ensure vehicle has a fully charged battery and functional charging system.
2. Visually inspect connectors and circuit wiring being worked on.
3. DO NOT disconnect battery or ECM. This will erase any fault codes stored in ECM.
4. DO NOT cause short circuits when performing electrical tests. This will set additional fault codes, making diagnosis of original problem more difficult.
5. DO NOT use a test light in place of a voltmeter.
6. When checking for spark, ensure coil wire is NOT more than 1/4" from chassis ground. If coil wire is more than 1/4" from chassis ground, damage to vehicle electronics and/or ECM may result.
7. DO NOT prolong testing of fuel injectors. Engine may hydrostatically (liquid) lock.
8. When a vehicle has multiple fault codes, always repair lowest number fault code first.

Using Scan Tester

1. Refer to manufacturer's operation manual for instructions in use of scan tester. Before entering on-board diagnostics, see «SERVICE PRECAUTIONS»(ref-18911-S00394626272001010800000). Turn ignition switch to OFF position. Locate Data Link Connector (DLC), next to fuse block. Connect power source terminal of scan tester to cigarette lighter socket.
2. Connect scan tester to DLC. (Scheme 30) Turn ignition switch to ON position. Read and record scan tester self-diagnosis output. Perform necessary repair(s). See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-18911-S19953172662001010800000).

Scheme 30

1. Before entering on-board diagnostics, see «SERVICE PRECAUTIONS»(ref-18911-S00394626272001010800000). Turn ignition switch to OFF position. Locate Data Link Connector (DLC), next to fuse block. Connect volt-meter positive lead to DLC terminal No. 1 and negative lead to terminal No. 12 (ground). (Scheme 30)
2. Turn ignition switch to ON position. Disclosure of ECM memory will begin. If 2 or more systems are non-functional, they are indicated by order of increasing code number. Indication is made by 12-volt pulses of voltmeter pointer. A constant repetition of short 12-volt pulses indicates system is normal. If system is abnormal, voltmeter will pulse between zero and 12 volts.
3. Signals will appear on voltmeter as long and short 12-volt pulses. Long pulses represent tens; short pulses represent ones. For example, 4 long pulses and 3 short pulses indicate Code 43. After recording fault code(s), perform necessary repair(s) to indicated circuit(s). See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-18911-S19953172662001010800000).

CLEARING CODES

Note. To clear codes using a scan tester, refer to owners manual supplied with scan tester.

Fault codes may be cleared by disconnecting negative battery cable for at least 10 seconds, allowing ECM to clear fault codes. Reconnect negative battery cable and check for codes to confirm repair.

CODE 11: OXYGEN (O2) SENSOR, 1-WIRE O2 SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 2. Start and warm engine to operating temperature. Disconnect O2 sensor connector. Connect DVOM between chassis ground and O2 sensor terminal. While repeatedly racing engine, measure O2 sensor output voltage. If voltage is not .6-1.0 volt, replace O2 sensor. If voltage is within specification, go to step 4.
2. Using scan tester, read O2 sensor voltage. While monitoring scan tester, accelerate to 4000 RPM. Suddenly decelerate. Scan tester should read .3 volt or less. Suddenly accelerate. Scan tester should read .5-1.0 volt. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
3. While monitoring scan tester, accelerate to 2000 RPM and decelerate to 700 RPM (idle). Scan tester should switch between .6-1.0 volt and .4 volt or less. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
4. Disconnect O2 sensor connector and ECM connector. Using DVOM, check for continuity between O2 sensor terminal and ECM connector terminal No. 4. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 11: OXYGEN (O2) SENSOR, 2-WIRE O2 SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 2. Start and warm engine to operating temperature. Disconnect O2 sensor connector. Connect DVOM between chassis ground and O2 sensor terminal No. 1. While repeatedly racing engine, measure O2 sensor output voltage. If voltage is not .6-1.0 volt, replace O2 sensor. If voltage is within specification, go to step 4.
2. Using scan tester, read O2 sensor voltage. While monitoring scan tester, accelerate to 4000 RPM. Suddenly decelerate. Scan tester should read .3 volt or less. Suddenly accelerate. Scan tester should read .5-1.0 volt. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
3. While monitoring scan tester, accelerate to 2000 RPM and decelerate to 700 RPM (idle). Scan tester should switch between .6-1.0 volt and .4 volt or less. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
4. Disconnect O2 sensor connector and ECM connector. Using DVOM, check for continuity between O2 sensor terminal No. 1 and ECM connector terminal No. 4. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
5. Using DVOM, check continuity between chassis ground and O2 sensor connector terminal No. 2. If continuity does not exist, replace O2 sensor. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 11: OXYGEN (O2) SENSOR, 4-WIRE O2 SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 3. Disconnect O2 sensor connector. On all models except Diamante, Stealth non-turbo and 3000GT non-turbo, install Test Harness (MB998464 ) between O2 sensor and O2 sensor connector. On all models, use DVOM to check resistance between specified O2 sensor connector heater terminals. See «O2 SENSOR 4-WIRE CONNECTOR TERMINAL ID»(ref-18911-S40952354162001010800000) table. O2 sensor resistance should be 20 ohms at 68°F (20°C). If resistance is not as specified, replace O2 sensor. If resistance is as specified, go to next step.
2. Using jumper wires, apply 12 volts to specified O2 sensor connector heater terminals. See «O2 SENSOR 4-WIRE CONNECTOR TERMINAL ID»(ref-18911-S40952354162001010800000) table. Using DVOM, check voltage between specified O2 sensor connector output terminals, while repeatedly racing engine. If voltage is not .6-1.0 volt, replace O2 sensor. If voltage is .6-1.0 volt, go to step 5. O2 SENSOR 4-WIRE CONNECTOR TERMINAL ID Application (1) Heater Terminals Output Terminals Turbo 1 & 3 2 & 4 Non-Turbo 3 & 4 1 & 2 (1) First terminal listed is positive. Second terminal listed is negative.
3. Start and warm engine to operating temperature. Using scan tester, read O2 sensor voltage. While monitoring scan tester, accelerate to 4000 RPM. Suddenly decelerate. Scan tester should read .3 volt or less. Suddenly accelerate. Scan tester should read .5-1.0 volt. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
4. While monitoring scan tester, accelerate to 2000 RPM and decelerate to 700 RPM (idle). Scan tester should switch between .6-1.0 volt and .4 volt or less. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
5. Disconnect O2 sensor connector. On Stealth and 3000GT, go to next step. On all other models, disconnect MPI relay connector. Using DVOM, check for continuity between specified O2 sensor connector terminals and MPI connector terminals. See «O2 SENSOR TO MPI WIRING HARNESS TERMINAL ID»(ref-18911-S17744768752001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to step 7. O2 SENSOR TO MPI WIRING HARNESS TERMINAL ID Application O2 Sensor Terminals MPI Terminals Diamante 3 5 All Other Models 2 2
6. Turn ignition switch to ON position. Using DVOM, check voltage between specified O2 sensor connector terminal and chassis ground. See «O2 SENSOR CONNECTOR VOLTAGE CIRCUIT ID»(ref-18911-S42567784612001010800000) table. If system voltage does not exist, repair wiring harness as necessary. If system voltage exists, go to next step. O2 SENSOR CONNECTOR VOLTAGE CIRCUIT ID Application Terminal No. Stealth & 3000GT (Non-Turbo) 3 Stealth & 3000GT (Turbo) 1
7. Using DVOM, check for continuity between specified O2 sensor connector terminals and ECM connector terminals. See «O2 SENSOR TO ECM WIRING HARNESS TERMINAL ID»(ref-18911-S15383328182001010800000) table. If continuity does not exist on either circuit, repair appropriate circuit for open or short to ground as necessary. If continuity exists, go to next step. O2 SENSOR TO ECM WIRING HARNESS TERMINAL ID Application O2 Sensor Terminals ECM Terminals Diamante 1 56 Stealth Non-Turbo & 3000GT Non-Turbo 1 56 Stealth Turbo & 3000GT Turbo 4 56
8. Disconnect O2 sensor connector. Using DVOM, check for continuity between specified O2 sensor connector terminal and chassis ground. See «O2 SENSOR CONNECTOR GROUND CIRCUIT ID»(ref-18911-S07888646112001010800000) table. If continuity does not exist, repair wiring harness as necessary. If no system or component malfunctions occur in preceding tests, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. O2 SENSOR CONNECTOR GROUND CIRCUIT ID Application Terminal No. All Models 2

CODE 12: AIRFLOW SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Note. Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscilloscope. If using a scan tester, go to step 3.

Scheme 31

1. If using scan tester, go to step 3. Disconnect Airflow Sensor (AFS) connector. Install Test Harness (MB991348 ) between AFS and AFS connector. Using engine analyzer with oscilloscope capability, connect special patterns probe to AFS connector terminal No. 3.
2. Start engine. Verify that wave form high frequency and low frequency patterns are of approximately the same length (time). (Scheme 31) Verify that wave length decreases and frequency increases as engine RPM increases. If conditions are not as specified, replace AFS. If conditions are as specified, go to step 4.
3. Warm vehicle to normal operating temperature. Ensure headlights and accessories are off. Ensure steering wheel is in straight-ahead position. Using scan tester, read Airflow Sensor (AFS) volume (frequency) value. See «AIRFLOW SENSOR VALUES»(ref-18911-S13767815912001010800000) table. Frequency should increase when engine is raced. If values are not as specified, replace AFS. If values are as specified, go to next step. AIRFLOW SENSOR VALUES Type Hz @ 700 RPM Hz @ 2000 RPM Diamante & Stealth SOHC 21-47 57-97 Stealth & 3000GT DOHC Non-Turbo 22-48 50-90 DOHC Turbo 22-48 68-108
4. On Stealth and 3000GT, go to step 8. On all other models, disconnect AFS connector and MPI relay connector. Using DVOM, check for continuity between specified AFS connector terminal and MPI relay connector terminal. See «AFS TO MPI TERMINAL WIRING HARNESS ID»(ref-18911-S10542212682001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. AFS TO MPI TERMINAL WIRING HARNESS ID Application AFS Terminal No. MPI Terminal No. All Models 4 3
5. Using DVOM, check for continuity between chassis ground and AFS connector terminal No. 5. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
6. Disconnect AFS connector and ECM connector. Using DVOM, check for continuity between specified AFS connector terminal and ECM connector terminal. See «AFS TO ECM WIRING HARNESS TERMINAL ID»(ref-18911-S00060739662001010800000) table. If continuity does not exist on specified circuit(s), repair appropriate circuit for open or short to ground as necessary. If continuity exists, go to next step. AFS TO ECM WIRING HARNESS TERMINAL ID Application AFS Terminal No. ECM Terminal No. All Models 3 70 All Models 7 19
7. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and AFS harness connector terminal No. 3 on all models. If voltage is not 4.8-5.2 volts, replace ECM. If voltage is as specified, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
8. Disconnect AFS connector. Turn ignition switch to ON position. Using DVOM, check voltage between specified terminal and chassis ground. See «AFS CONNECTOR POWER SUPPLY CIRCUIT ID»(ref-18911-S27353520072001010800000) table. If system voltage does not exist, repair wiring harness as necessary. If system voltage exists, go to next step. AFS CONNECTOR POWER SUPPLY CIRCUIT ID Application Terminal No. Stealth & 3000GT 4
9. With ignition switch in ON position, use DVOM to check voltage between specified terminal and chassis ground. See «AFS CONNECTOR VOLTAGE CIRCUIT ID»(ref-18911-S09305616172001010800000) table. If voltage is not 4.8-5.2 volts, repair wiring harness as necessary. If voltage is as specified, go to next step. AFS CONNECTOR VOLTAGE CIRCUIT ID Application Terminal No. All Models 3
10. Using DVOM, check for continuity between specified AFS connector terminal and chassis ground. See «AFS CONNECTOR GROUND CIRCUIT ID»(ref-18911-S11121018772001010800000) table. If continuity does not exist, repair wiring harness as necessary. Go to next step. AFS CONNECTOR GROUND CIRCUIT ID Application Terminal No. All Models 5
11. Disconnect AFS connector and ECM connector. Using DVOM, check for continuity between specified AFS connector terminal and ECM connector terminal. See «ECM TO AFS WIRING HARNESS TERMINAL»(ref-18911-S09225720362001010800000) table. If continuity does not exist on specified circuit(s), repair appropriate circuit for open or short to ground as necessary. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. ECM TO AFS WIRING HARNESS TERMINAL Application ECM Terminal No. AFS Terminal No. Stealth & 3000GT 19 7 Diamante 57 7

CODE 13: INTAKE AIR TEMPERATURE SENSOR

Note. On all models, intake air temperature sensor is built into airflow sensor. For code 13 test purposes, the airflow sensor will be referred to as the intake air temperature sensor. For component terminal identification, see AIRFLOW SENSOR under TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Scheme 32

1. If using scan tester, go to step 3. Disconnect Intake Air Temperature (IAT) sensor connector. Using a thermometer, check engine compartment ambient temperature. Using DVOM, check resistance between specified IAT sensor terminals. See «IAT SENSOR TERMINAL ID»(ref-18911-S01420719982001010800000) table. Resistance should be 6000 ohms at 32°F (0°C), 2700 ohms at 68°F (20°C) or 400 ohms at 176°F (80°C). If resistance is not as specified, replace IAT sensor. If resistance is as specified, go to next step. IAT SENSOR TERMINAL IDENTIFICATION Application Terminals No. All Models 5 & 6
2. Using a hair dryer, warm IAT sensor while monitoring DVOM. Resistance should decrease evenly as temperature rises. If resistance remains unchanged, replace IAT sensor. If resistance changes, go to step 4.
3. Turn ignition switch to ON or RUN position. Using a thermometer, check engine compartment ambient temperature. Using scan tester, read Intake Air Temperature (IAT) sensor temperature. See «IAT SENSOR TEMPERATURE»(ref-18911-S40399608112001010800000) table. If temperatures are not as specified, replace IAT sensor. If temperatures are as specified, go to next step. IAT SENSOR TEMPERATURE Ambient Temperature Standard Value -4°F (-20°C) -20°C 32°F (0°C) 0°C 68°F (20°C) 20°C 104°F (40°C 40°C 176°F (80°C) 80°C
4. Disconnect IAT sensor connector. Using DVOM, check for continuity between chassis ground and specified IAT sensor connector terminal. See «IAT SENSOR GROUND CIRCUIT TERMINAL ID»(ref-18911-S22225177862001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. IAT SENSOR GROUND CIRCUIT TERMINAL ID Application Terminal No. All Models 5
5. On Stealth and 3000GT, go to next step. On all other models, with IAT sensor connector and ECM connector disconnected, check for continuity between specified IAT sensor connector terminal and ECM connector terminal. See «IAT TO ECM WIRING HARNESS TERMINAL ID»(ref-18911-S04302369372001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. IAT TO ECM WIRING HARNESS TERMINAL ID Application IAT Connector Terminal No. ECM Connector Terminal No. All Models 6 52
6. Turn ignition switch to ON position. Check voltage between chassis ground and specified IAT sensor connector. See «IAT SENSOR CONNECTOR VOLTAGE SUPPLY CIRCUIT TERMINAL ID»(ref-18911-S18298234802001010800000) table. If voltage is not 4.5-4.9 volts, replace ECM. If voltage is as specified, replace IAT sensor. IAT SENSOR CONNECTOR VOLTAGE SUPPLY CIRCUIT TERMINAL ID Application Terminal No. All Models 6

CODE 14: THROTTLE POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 3. Disconnect Throttle Position Sensor (TPS) connector. Using DVOM, check resistance between TPS terminals No. 1 and 4. If resistance is not 3500-6500 ohms, replace TPS. If resistance is as specified, go to next step
2. Check resistance between specified TPS terminals. See «TPS TERMINAL ID»(ref-18911-S19366236122001010800000) table. While monitoring DVOM, slowly open throttle from idle to fully open position. If resistance does not change smoothly, replace TPS. If resistance changes smoothly, go to step 4. TPS TERMINAL ID Application Terminals No. All Models 2 & 4
3. Turn ignition switch to ON position. Using scan tester, read Throttle Position Sensor (TPS) voltage. With throttle at idle, voltage should read .3-1.0 volt. Voltage should increase while slowly opening throttle. At wide open throttle, voltage should read 4.5-5.5 volts. If voltage is not as specified, replace TPS. If voltage is as specified, go to next step.
4. On Stealth and 3000GT, go to step 7. On all other models, disconnect TPS connector. Using DVOM, check continuity between chassis ground and specified TPS connector terminal. See «TPS CONNECTOR GROUND CIRCUIT ID»(ref-18911-S34933312852001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. TPS CONNECTOR GROUND CIRCUIT ID Application Terminal No. All Models 4
5. Disconnect TPS connector and ECM connector. Check for continuity between specified TPS connector terminal and ECM connector terminal. See «TPS TO ECM WIRING HARNESS TERMINAL ID»(ref-18911-S40046788952001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. TPS TO ECM WIRING HARNESS TERMINAL ID Application TPS Terminal No. ECM Terminal No. Diamante 1 61 2 64
6. Check voltage between chassis ground and specified TPS connector terminal. See «TPS VOLTAGE CIRCUIT ID»(ref-18911-S20604258492001010800000) table. If voltage is not 4.8-5.2 volts, replace ECM. If voltage is as specified, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. «TESTS W/O CODES»(ref-18913) article. TPS VOLTAGE CIRCUIT ID Application TPS Terminal No. Diamante 1
7. Disconnect TPS connector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and specified TPS connector terminal. See «TPS VOLTAGE SUPPLY ID»(ref-18911-S03697368902001010800000) table. If voltage is not 4.8-5.2 volts, repair wiring harness as necessary. If voltage is as specified, go to next step. TPS VOLTAGE SUPPLY ID Application TPS Terminal No. Stealth & 3000GT 4
8. Check continuity between chassis ground and specified TPS connector terminal. See «TPS CONNECTOR GROUND CIRCUIT ID»(ref-18911-S34933312852001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. TPS CONNECTOR GROUND CIRCUIT ID Application Terminal No. All Models 4
9. With TPS connector and ECM connector disconnected, check for continuity between specified TPS connector terminal and ECM connector terminal. See «ECM TO TPS HARNESS ID»(ref-18911-S30429168832001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. ECM TO TPS HARNESS ID Application ECM Terminal No. TPS Terminal No. Stealth & 3000GT 64 2 Diamante 9 2

CODE 15: IDLE SPEED CONTROL POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 3. Disconnect Idle Speed Control (ISC) motor position sensor connector. Using DVOM, check resistance between ISC motor position sensor terminals No. 2 and 3. If resistance is not 4000-6000 ohms, replace ISC motor position sensor. If resistance is as specified, go to next step. CAUTION: Apply only 6 volts DC or less to ISC motor connector. Higher voltage could cause servo gears to lock up.
2. Disconnect ISC motor connector. Connect a 6-volt DC power supply between ISC motor connector terminals No. 1 and 2 to operate ISC motor. Check resistance between ISC motor position sensor terminals No. 3 and 5. Ensure ISC motor position sensor resistance changes smoothly as motor extends and retracts. If resistance does not change smoothly, replace ISC motor assembly. If resistance changes smoothly, go to step 4.
3. Ensure engine coolant temperature is 185-205°F (85-95°C). Place transmission in Park or Neutral. Turn off all accessories except A/C. Ensure A/C clutch is operating when A/C system is on. With engine at idle, use scan tester to read Idle Speed Control (ISC) motor position sensor voltage. See «ISC VOLTAGE SPECIFICATIONS»(ref-18911-S05311450232001010800000) table. If voltage is not as specified, replace IAC motor position sensor. If voltage is as specified, go to next step. ISC VOLTAGE SPECIFICATIONS Application A/C Switch Position Standard Voltage All Models Off .5-1.3 On .9-2.3 (1) .9-2.3 (1) On A/T models only, apply brakes, place transmission selector in "D" position and A/C switch in ON position.
4. Disconnect ISC motor position sensor connector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and sensor connector terminal No. 2. Check voltage between chassis ground and sensor connector terminal No. 6. Voltage should be 4.8-5.2 volts on both circuits. If voltage is not as specified, repair appropriate wiring harness circuit(s) as necessary. If voltage is as specified, go to next step.
5. Check for continuity between chassis ground and sensor connector terminal No. 3. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 21: COOLANT TEMPERATURE SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 2. Remove Coolant Temperature Sensor (CTS) from intake manifold. Submerge temperature sensing portion of CTS in hot water. Using DVOM, check resistance across CTS terminals. See «CTS RESISTANCE SPECIFICATIONS»(ref-18911-S13553491382001010800000) table. If resistance is not as specified, replace CTS. If resistance is as specified, go to step 3. CTS RESISTANCE SPECIFICATIONS Water Temperature Approximate Ohms 32°F (0°C) 5800 68°F (20°C) 2400 104°F (40°C) 1100 176°F (80°C) 300
2. Turn ignition switch to ON or RUN position. Using a thermometer, check engine compartment ambient temperature. Using scan tester, read Coolant Temperature Sensor (CTS) voltage. See «CTS VOLTAGE SPECIFICATIONS»(ref-18911-S06121703392001010800000) table. If voltage is not within specifications, replace CTS. If voltage is within specification, go to next step. CTS VOLTAGE SPECIFICATIONS Ambient Temperature Standard Value °F (°C) -4°F (-20°C) -20°C 32°F (0°C) 0°C 68°F (20°C) 20°C 104°F (40°C 40°C 176°F (80°C) 80°C
3. Disconnect CTS connector. Using DVOM, check continuity between chassis ground and specified connector terminal. See «CTS GROUND CIRCUIT TERMINAL ID»(ref-18911-S29529162132001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CTS GROUND CIRCUIT TERMINAL ID Application Terminal No. All Models 2
4. On Stealth, and 3000GT, go to next step. On all other models, Disconnect CTS connector and ECM connector. Check continuity between specified CTS connector terminals and ECM connector terminals. See «CTS TO ECM WIRING HARNESS TERMINAL ID»(ref-18911-S37040809502001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CTS TO ECM WIRING HARNESS TERMINAL ID Application CTS Terminal No. ECM Terminal No. All Models 1 63
5. Turn ignition switch to ON position. Check voltage between chassis ground and specified CTS connector terminal. See «CTS VOLTAGE CIRCUIT ID»(ref-18911-S28261613512001010800000) table. If voltage is not 4.5-4.9 volts, replace ECM. If voltage is as specified, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CTS VOLTAGE CIRCUIT ID

CODE 22: CRANKSHAFT POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Note. Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscilloscope. If using a scan tester, go to step 3.

Scheme 33

Scheme 34

1. On Diamante, disconnect Crankshaft/Camshaft Position (CKP/CMP) sensor connector. Install Test Harness (MB991348) between sensor and connector. On all models, using engine analyzer with oscilloscope capability, connect special patterns probe to specified connector terminal. See «CKP PATTERN PICKUP TERMINAL ID»(ref-18911-S37967154042001010800000) table. CKP PATTERN PICKUP TERMINAL ID Application Terminal No. All Models 2
2. Start engine. Compare oscilloscope wave pattern with known-good wave pattern. (Scheme 33) Verify that wave length (time) decreases as engine RPM increases. If a wave pattern is output and it fluctuates to left or right, check for loose timing belt or an abnormality in sensor pickup disc. If a rectangular wave pattern is output even when engine is not started, substitute known-good CKP sensor. Repeat test. If wave pattern is still abnormal, go to step 5.
3. Connect an engine tachometer. Crank engine. Ensure ignition coil primary current toggles on and off. Using tachometer and scan tester, compare cranking speed and scan tester read out. If engine fails to start and tachometer reads zero RPM when engine is cranked, check for broken timing belt or faulty CKP sensor. If CKP sensor is suspected, substitute known-good CKP sensor. Repeat test procedure. If engine fails to start, tachometer reads zero RPM, and ignition coil primary current fails to toggle on and off, check for faulty ignition coil, ignition circuit or power transistor. If engine starts and readouts agree, go to next step.
4. Ensure A/C switch is in ON position to activate closed throttle position switch. Allow engine to idle. Check coolant temperature. Using scan tester, read idle speed. See «IDLE RPM SPECIFICATIONS»(ref-18911-S10320232052001010800000) table. If RPM is not to specification, check for faulty coolant temperature sensor, basic idle speed adjustment, or idle air control motor. If RPM is within specifications, go to next step. IDLE RPM SPECIFICATIONS Coolant Temperature Engine RPM -4°F (-20°C): All Models 1300-1500 32°F (0°C): All Models 1250-1450 68°F (20°C) Diamante DOHC, Stealth DOHC & 3000GT 1100-1300 Diamante SOHC, Stealth SOHC 1050-1250 104°F (40°C) Diamante DOHC, Stealth DOHC & 3000GT 950-1150 Diamante SOHC, Stealth SOHC 850-1050 176°F (80°C): All Models 600-800
5. Disconnect CKP/CMP sensor connector and Ignition (IG) switch connector. Using DVOM, check for continuity between CKP/CMP sensor connector terminal No. 2 and IG switch connector terminal No. 3. (Scheme 34) If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to step 8.
6. On all other models except Diamante, go to next step. Disconnect CKP/CMP connector and MPI relay connector. Using DVOM, check for continuity between CKP/CMP connector terminal No. 3 and MPI relay connector terminal No. 5. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to step 8.
7. On all other models, disconnect CKP/CMP sensor connector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR VOLTAGE TERMINAL ID»(ref-18911-S00509791032001010800000) table. If battery voltage does not exist, repair ignition circuit between CKP/CMP sensor connector and Ignition switch. If battery voltage exists, go to next step. CKP SENSOR VOLTAGE TERMINAL ID Application Terminal No. All Models 3
8. With CKP/CMP sensor connector disconnected, check for continuity between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR GROUND CIRCUIT TERMINAL ID»(ref-18911-S20089343822001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CKP SENSOR GROUND CIRCUIT TERMINAL ID Application Terminal No. Diamante SOHC & Stealth SOHC 4 All Other Models 1
9. On Stealth and 3000GT, go to next step. On Diamante, with CKP/CMP sensor connector and ECM connector disconnected, check for continuity between specified CKP/CMP sensor connector terminal and ECM connector terminal. See «CKP TO ECM CONNECTOR TERMINAL ID»(ref-18911-S38210727602001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CKP TO ECM CONNECTOR TERMINAL ID Application CKP Terminal No. ECM Terminal No. Diamante 2 69 All Other Models 3 69
10. With ignition switch in ON position, check for voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CKP SENSOR SUPPLY CIRCUIT ID»(ref-18911-S23995903312001010800000) table. If 4.8-5.2 volts do not exist, replace ECM. If voltage is to specification and CKP sensor is suspected, replace CKP sensor. CKP SENSOR SUPPLY CIRCUIT ID Application Terminal No. All Models 2

CODE 23: CAMSHAFT POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Note. Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscilloscope. Manufacturer does not provide procedures for testing component using a scan tester.

Scheme 35

1. On all models except Stealth and 3000GT, disconnect Crankshaft/Camshaft Position (CKP/CMP) sensor connector. Install Test Harness (MB991348) between sensor and connector. On all models, using engine analyzer with oscilloscope capability, connect special patterns probe to specified connector terminal. See «CMP PATTERN PICKUP TERMINAL ID»(ref-18911-S29787653132001010800000) table. CMP PATTERN PICKUP TERMINAL ID Application Terminal No. Diamante SOHC, Stealth & 3000GT 1 Diamante DOHC 2
2. Start engine. Compare oscilloscope wave pattern with known-good wave pattern. (Scheme 35) Verify that wave length (time) decreases as engine RPM increases. If a wave pattern is output and it fluctuates to left or right, check for loose timing belt or an abnormality in sensor pickup disc. If a rectangular wave pattern is output even when engine is not started, substitute known-good CMP sensor. Repeat test. If wave pattern is still abnormal, go to next step.
3. On all other models except Diamante, go to next step. Disconnect CKP/CMP connector and MPI relay connector. Using DVOM, check for continuity between CKP/CMP connector terminal No. 3 and MPI relay connector terminal No. 5. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to step 6.
4. On all other models, disconnect CKP/CMP sensor connector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CMP SENSOR VOLTAGE TERMINAL ID»(ref-18911-S22591432302001010800000) table. If battery voltage does not exist, repair ignition circuit between CKP/CMP sensor connector and Ignition switch. If battery voltage exists, go to next step. CMP SENSOR VOLTAGE TERMINAL ID Application Terminal No. All Models 3
5. With CKP/CMP sensor connector disconnected, check for continuity between chassis ground and specified CKP/CMP sensor connector terminal. See «CMP SENSOR GROUND CIRCUIT TERMINAL ID»(ref-18911-S05483792492001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CMP SENSOR GROUND CIRCUIT TERMINAL ID Application Terminal No. Diamante SOHC & Stealth SOHC 4 All Other Models 1
6. On Stealth and 3000GT, go to next step. On all other models, with CKP/CMP sensor connector and ECM connector disconnected, check for continuity between specified CKP/CMP sensor connector terminal and ECM connector terminal. See «CMP TO ECM CONNECTOR TERMINAL ID»(ref-18911-S14110956802001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. CMP TO ECM CONNECTOR TERMINAL ID Application CMP Terminal No. ECM Terminal No. Diamante SOHC 1 68 DOHC 2 68 All Other Models 4 68
7. With ignition switch in ON position, check for voltage between chassis ground and specified CKP/CMP sensor connector terminal. See «CMP SENSOR SUPPLY CIRCUIT ID»(ref-18911-S33853008832001010800000) table. If 4.8-5.2 volts do not exist, replace ECM. If voltage is as specified, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. CMP SENSOR SUPPLY CIRCUIT ID Application Terminal No. SOHC 1 DOHC 2

CODE 24: VEHICLE SPEED SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Scheme 36

Scheme 37

Scheme 38

1. Manufacturer does not provide Vehicle Speed Sensor (VSS) testing procedures using scan tester. VSS is located in speedometer. VSS component testing procedures using DVOM require removal of instrument panel. Removal and installation of instrument panel is basically an unbolt and bolt-on procedure.
2. On Stealth turbo and 3000GT turbo, go to next step. On all other models, use DVOM to check continuity between indicated VSS terminals. (Scheme 36), (Scheme 37) or (Scheme 38). Ensure continuity pulses on and off 4 times per speedometer shaft revolution. If continuity is not as specified, replace VSS. If continuity is as specified, go to step 4.
3. Remove VSS. Connect battery, resistor (3-10 ohms) and voltmeter to indicated terminals. (Scheme 36), (Scheme 37) or (Scheme 38). Ensure voltage pulses 4 times per speedometer shaft revolution. If voltage is not as specified, replace VSS. If voltage is as specified, go to next step.
4. Disconnect ECM connector. Using DVOM, check continuity between chassis ground and specified ECM connector terminal. See «VSS OUTPUT CIRCUIT ID»(ref-18911-S20679343492001010800000) table. Move vehicle. Ensure continuity pulses on and off 4 times per tire revolution. If continuity is as specified: On Stealth and 3000GT, conditions required to set code are not present at this time, test is complete; on all other models, go to step 7. If continuity is not as specified: Stealth and 3000GT, go to step 6. On all other models, go to next step. VSS OUTPUT CIRCUIT ID Application Terminal No. All Models 66
5. With ECM connector disconnected, disconnect VSS connector. Ground ECM connector VSS output terminal. See «VSS OUTPUT CIRCUIT ID»(ref-18911-S20679343492001010800000) table. Using DVOM, check for continuity between chassis ground and specified VSS connector terminal. See «ECM TO VSS CIRCUIT ID»(ref-18911-S02677909722001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. ECM TO VSS CIRCUIT ID Application Terminal No. All Models 9
6. With VSS connector disconnected, check for continuity between chassis ground and specified VSS connector terminal. See «VSS GROUND CIRCUIT ID»(ref-18911-S26095935782001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. VSS GROUND CIRCUIT ID Application Terminal No. Diamante 13 Stealth & 3000GT 102
7. With VSS connector and ECM connector disconnected, turn ignition switch to ON position. Using DVOM, check for voltage between chassis ground and specified VSS connector terminal. See «VSS VOLTAGE FEED CIRCUIT ID»(ref-18911-S40048602382001010800000) table. If voltage is not 4.5-4.9 volts, replace ECM. If voltage is as specified, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. VSS VOLTAGE FEED CIRCUIT ID Application Terminal No. Stealth & 3000GT 109 Diamante 9

CODE 25: BAROMETRIC PRESSURE SENSOR

Note. Barometric (BARO) pressure sensor is built into airflow sensor. For code 25 test purposes, the airflow sensor will be referred to as the BARO pressure sensor. For component terminal identification, see AIRFLOW SENSOR under TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Manufacturer does not provide component testing procedure without scan tester. Turn ignition switch to ON position. Using scan tester, read sensor pressure. See «BARO PRESSURE SENSOR SPECIFICATIONS»(ref-18911-S13067775752001010800000) table. If pressure is not as specified, replace BARO pressure sensor. If pressure is as specified, go to next step. BARO PRESSURE SENSOR SPECIFICATIONS Altitude: Ft. (M) Pressure: In. Hg 0 (0) 29.92 1969 (600) 27.95 3937 (1200) 25.98 5906 (1800) 24.02
2. Disconnect BARO pressure sensor connector. Using DVOM, check for continuity between chassis ground and specified BARO pressure sensor connector terminal. See «BARO PRESSURE SENSOR GROUND CIRCUIT ID»(ref-18911-S34938462602001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. BARO PRESSURE SENSOR GROUND CIRCUIT ID Application Terminal No. All Models 5
3. On Stealth and 3000GT, go to step 5. On all other models, with BARO pressure sensor disconnected, disconnect ECM connector. Check for continuity between specified ECM connector terminal and BARO pressure sensor connector terminal. See «BARO PRESSURE SENSOR TO ECM CIRCUIT ID»(ref-18911-S27606287412001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. BARO PRESSURE SENSOR TO ECM CIRCUIT ID Application BARO Terminal No. ECM Terminal No. Diamante 1 61 2 65 All Models 2 65
4. With BARO pressure sensor connector and ECM connector disconnected, turn ignition switch to ON position. Check for voltage between chassis ground and BARO pressure sensor connector terminal No. 1. If voltage is not 4.8-5.2 volts, replace ECM. If voltage is as specified, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
5. With BARO pressure sensor connector disconnected, turn ignition switch to ON position. Check for voltage between chassis ground and specified BARO pressure sensor connector terminal. See «BARO PRESSURE SENSOR POWER SUPPLY CIRCUIT ID»(ref-18911-S23458227282001010800000) table. If voltage is not 4.8-5.2 volts, repair wiring harness as necessary. If voltage is as specified, go to next step. BARO PRESSURE SENSOR POWER SUPPLY CIRCUIT ID Application Terminal No. All Models 1
6. With BARO pressure sensor connector and ECM connector disconnected, ground ECM connector terminal No. 16 (terminal No. 65 on Stealth and 3000GT). Using DVOM, check for continuity between chassis ground and specified BARO pressure sensor connector terminal. See «ECM TO BARO PRESSURE SENSOR GROUND CIRCUIT ID»(ref-18911-S42849026492001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. ECM TO BARO PRESSURE SENSOR GROUND CIRCUIT ID Application Terminal No. Stealth & 3000GT 1

CODE 31: KNOCK SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Manufacturer does not provide component testing procedure using scan tester. On Diamante, Stealth and 3000GT, go to next step.
2. Disconnect knock sensor connector and ECM connector. Ground ECM connector terminal No. 58. Using DVOM, check continuity between chassis ground and knock sensor connector terminal No. 1. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
3. With knock sensor connector disconnected, check for continuity between chassis ground and knock sensor connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Test is complete.

CODE 32: MAP SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Manufacturer does not provide component testing procedure without scan tester. Ensure coolant temperature is 176-203°F (80-95°C). Ensure all accessories are off, transmission is in Neutral, and ignition switch is in ON position. Using scan tester, read intake manifold plenum pressure. See «INTAKE MANIFOLD PLENUM PRESSURE SPECIFICATIONS»(ref-18911-S14356295252001010800000) table. If conditions are not as specified, replace Manifold Absolute Pressure (MAP) sensor. If conditions are as specified, go to next step. INTAKE MANIFOLD PLENUM PRESSURE SPECIFICATIONS Engine State Altitude Ft. (M) Pressure: In. Hg Off 0 (0) 29.92 1969 (600) 27.95 3937 (1200) 25.98 5906 (1800) 24.02 Idle (750 RPM) N/A 6.70-10.62 Suddenly Raced N/A (1) (1) Pressure should increase.
2. Disconnect MAP sensor connector. Using DVOM, check continuity between chassis ground and MAP sensor connector terminal No. 3. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
3. With MAP sensor connector disconnected, disconnect ECM connector. Ground ECM connector terminal No. 70. Using DVOM, check continuity between chassis ground and MAP sensor connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
4. With MAP sensor connector and ECM connector disconnected, turn ignition switch to ON position. Check voltage between chassis ground and MAP sensor connector terminal No. 1. If 4.8-5.2 volts do not exist, replace ECM. If voltage is as specified, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 39: OXYGEN (O2) SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 3. Disconnect O2 sensor connector. Install Test Harness (MB998464 ) between O2 sensor and O2 sensor connector. Using DVOM, check resistance between O2 sensor connector terminals No. 1 and 3. O2 sensor resistance should be 20 ohms at 68°F (20°C). If resistance is not as specified, replace O2 sensor. If resistance is as specified, go to next step.
2. Start and warm engine to operating temperature. Using jumper wires, ground O2 sensor connector terminal No. 3 and apply 12 volts to O2 sensor connector terminal No. 1. Using DVOM, check voltage between O2 sensor connector terminals No. 2 and 4 while repeatedly racing engine. If voltage is not .6-1.0 volt, replace O2 sensor. If voltage is as specified, go to step 5.
3. Start and warm engine to operating temperature. Using scan tester, read O2 sensor voltage. While monitoring scan tester, accelerate to 4000 RPM. Suddenly decelerate. Scan tester should read .2 volt or less. Suddenly accelerate. Scan tester should read .6-1.0 volt. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
4. While monitoring scan tester, accelerate to 2000 RPM and decelerate to 700 RPM (idle). Scan tester should switch between .6-1.0 volt and .4 volt or less. If voltage is not as specified, replace O2 sensor. If voltage is as specified, go to next step.
5. With O2 sensor connector disconnected, turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and O2 sensor connector terminal No. 1. If system voltage does not exist, repair wiring harness as necessary. If system voltage exists, go to next step.
6. Using DVOM, check for continuity between O2 sensor connector terminal No. 4 and ECM connector terminal No. 56. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
7. With O2 sensor connector disconnected, check for continuity between chassis ground O2 sensor connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set fault is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 41: FUEL INJECTOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Scheme 39

1. Using a stethoscope or long-bladed screwdriver, listen for clicking sound from each injector while engine is running or being cranked. If no sound is heard from injector(s), check injector connections. If connections are not okay, repair connections as necessary. If connections are okay, go to next step.
2. Disconnect injector connector. Using DVOM, check resistance across injector terminals. If resistance is not 13-16 ohms, replace injector. If resistance is as specified, go to next step.
3. Using scan tester, read injector drive time while cranking engine. See «INJECTOR CRANKING DRIVE TIME SPECIFICATIONS»(ref-18911-S32871353432001010800000) table. Go to next step. INJECTOR CRANKING DRIVE TIME SPECIFICATIONS Coolant Temperature Drive Time 32°F (0°C) Diamante DOHC 17-20 ms Diamante SOHC, Stealth Non-Turbo & 3000GT Non-Turbo 14-16 ms Stealth Turbo & 3000GT Turbo 9 ms 68°F (20°C) Diamante DOHC, Stealth DOHC & 3000GT 38-41 ms Diamante DOHC, Stealth DOHC Non-Turbo & 3000GT Non-Turbo 45-46ms Stealth Turbo & 3000GT Turbo 28 ms 176°F (80°C) Stealth SOHC & Turbo & 3000GT Turbo 9-10 ms Diamante DOHC 11 ms Stealth SOHC 8 ms Stealth Turbo & 3000GT Turbo 6 ms
4. Ensure coolant temperature is at 176-205°F (80-95°C), all accessories are off and transaxle is in Neutral position. Using scan tester, read injector drive time under specified engine conditions. See «INJECTOR OPERATING DRIVE TIME SPECIFICATIONS»(ref-18911-S14690966972001010800000) table. Go to next step. INJECTOR OPERATING DRIVE TIME SPECIFICATIONS Engine State Drive Time 750 RPM Diamante, Stealth Non-Turbo & 3000GT Non-Turbo 2.3-3.5 ms Stealth Turbo 1.6-3.8 ms 2000 RPM Stealth Turbo & 3000GT Turbo 1.4-2.6 ms All Other Models 2.0-3.3 ms Suddenly Accelerated (1) (1) Drive time should increase.
5. Allow engine to idle after warm up. Using scan tester, shut off injectors in sequence. Idle should change when good injectors are shut off. If idle state does not change, check injector connection, spark plug and cable, and cylinder compression. If conditions are not as specified in preceding steps, go to next step.
6. On Stealth and 3000GT, go to step 8. On Diamante, disconnect MPI relay connector and injector connector at faulty injector. Using DVOM, check for continuity between specified MPI relay connector terminal and injector connector terminal. See «MPI TO FUEL INJECTOR HARNESS TERMINAL ID»(ref-18911-S22343158472001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. MPI TO FUEL INJECTOR HARNESS TERMINAL ID Application MPI Terminal No. Fuel Injector Terminal No. Diamante 5 1 All Other Models 2 1
7. Using a DVOM, check for continuity between injector connector terminal No. 2 (terminal No. 5 for No. 4 injector or terminal No. 6 for No. 6 injector on Diamante DOHC, or terminal No. 3 for No. 5 injector or terminal No. 4 for No. 6 injector on Diamante SOHC), and specified ECM connector terminal. See «INJECTOR TO ECM CIRCUIT ID»(ref-18911-S04184471882001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article. INJECTOR TO ECM CIRCUIT ID Application Injector No. ECM Terminal No. Diamante 1 1 2 14 3 2 4 15 5 3 6 16 All Other Models 1 1 2 14 3 2 4 15
8. On Stealth and 3000GT, go to step 10. Disconnect injector connector at faulty injector. Turn ignition switch to ON position. Using DVOM, check for voltage between chassis ground and injector connector terminal No. 1. If battery voltage does not exist, repair wiring harness as necessary. If battery voltage exists, go to next step.
9. With injector connector disconnected, disconnect ECM connector. Check for continuity between injector connector terminal No. 2 and ECM connector terminal No. 51 for injector No. 1, No. 52 for injector No. 2, No. 60 for injector No. 3, or No. 61 for injector No. 4. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
10. On Stealth and 3000GT, go to step 15. Turn ignition switch to ON position. With MPI relay connector connected, check for voltage between chassis ground and MPI relay connector terminals No. 4 and 5. If battery voltage does not exist, check MPI relay. If battery voltage exists: on turbo models, go to next step; on non-turbo models, go to step 13.
11. Disconnect MPI relay resistor connector. Turn ignition switch to ON position. Check for voltage between chassis ground and relay resistor connector terminal No. 3. If battery voltage does not exist, repair wiring harness between MPI relay and relay resistor. If battery voltage exists, go to next step.
12. With relay resistor connector disconnected and injector connector connected, check resistance between relay resistor terminals No. 3 and 1 for injector No. 1, No. 3 and 4 for injector No. 2, No. 3 and 5 for injector No. 3, or No. 3 and 6 for injector No. 4. If resistance is not 5.5-6.5 ohms at 68°F (20°C), replace relay resistor. If resistance is as specified, go to next step.
13. On turbo and non-turbo models, disconnect injector connector at faulty injector. Using DVOM, check voltage between chassis ground and injector connector terminal No. 1 (non-turbo) or injector connector terminal No. 2 (turbo). If battery voltage does not exist, repair wiring harness as necessary. If battery voltage exists, go to next step.
14. With injector connector disconnected, disconnect ECM connector. Ground ECM connector terminal No. 51 for injector No.1, No. 52 for injector No. 2, No. 60 for injector No. 3, or No. 61 for injector No. 4. Check for continuity between chassis ground and injector connector terminal No. 1 (non-turbo) or No. 2 (turbo). If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
15. Disconnect MPI relay resistor connector. Turn ignition switch to ON position. Using DVOM, check for voltage between chassis ground and resistor connector terminal No. 2. (Scheme 39) If battery voltage does not exist, repair wiring harness as necessary between MPI relay resistor connector and MPI relay. If battery voltage exists, reconnect MPI relay resistor connector. Go to next step.
16. If faulty injector is on rear injector bank, go to next step. Disconnect injector connector at faulty front injector. Turn ignition switch to ON position. Using DVOM, check voltage between chassis ground and injector connector terminal No. 1. If battery voltage does not exist, repair wiring harness as necessary between injector connector and MPI relay. If voltage exists, go to step 18.
17. Disconnect rear bank injector connector. Using DVOM, check voltage between chassis ground and injector connector terminal. 1. If battery voltage does not exist, repair wiring harness as necessary between injector connector and MPI relay. If voltage exists, go to step 19.
18. With injector connector disconnected, disconnect ECM connector. Ground ECM connector terminal No. 1 for injector No. 1, No. 2 for injector No. 3, or No. 3 for injector No. 3. Using DVOM, check for continuity between chassis ground and injector connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary between appropriate injector connector and ECM connector terminal. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
19. With rear bank injector connector disconnected, disconnect ECM connector. Ground ECM connector terminal No. 14 for injector No. 2, No. 15 for injector No. 4, or No. 16 for injector No. 6. Using DVOM, check for continuity between chassis ground and rear bank injector connector terminal No. 2 for injector No. 2, No. 3 for injector No. 4, or No. 4 for injector No. 6. If continuity does not exist, repair wiring harness between rear bank injector connector and ECM connector. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 42: FUEL PUMP

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Turn ignition switch to ON position. Using a scan tester, actuate fuel pump. Crank engine with fuel pump actuated. Operating noise should be heard. Pinch fuel pump return hose and feel for fuel flow pulsations. If operating noise is not heard or fuel flow is not felt, replace fuel pump. If conditions are as specified, go to next step.
2. Apply 12 volts to fuel pump check terminal. If fuel pump operates, go to step 5. If fuel pump does not operate, go to next step.
3. Disconnect fuel pump connector, located at front of fuel tank. Using DVOM, check for continuity between chassis ground and specified fuel pump connector terminal. See «FUEL PUMP GROUND CIRCUIT ID»(ref-18911-S00177872822001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. FUEL PUMP GROUND CIRCUIT ID Application Terminal No. All Models 1
4. Ground fuel pump check terminal. With fuel pump connector disconnected, disconnect MPI relay connector. Check for continuity between chassis ground and specified fuel pump connector terminal. See «FUEL PUMP DRIVE CIRCUIT ID»(ref-18911-S26310990092001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. FUEL PUMP DRIVE CIRCUIT ID Application Terminal No. All Models 2
5. Disconnect MPI relay connector. Check voltage between chassis ground and specified MPI relay connector terminal. See «MPI RELAY VOLTAGE SUPPLY TERMINAL ID»(ref-18911-S38990900322001010800000) table. With ignition switch in OFF position, voltage should be zero. With engine cranking, voltage should be 8.0 volts or more. If voltage is not as specified, repair ignition switch or wiring harness as necessary. If voltage is as specified, go to next step. MPI RELAY VOLTAGE SUPPLY TERMINAL ID Application Terminal No. All Models 7
6. Turn ignition to OFF position. With MPI connector disconnected, disconnect ECM connector. Ground specified ECM connector terminal and check continuity between chassis ground and specified MPI relay connector terminal. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
7. On all other models, with fuel pump connector and MPI relay connector disconnected, ground fuel pump check terminal. Check for continuity between chassis ground and MPI relay connector terminal No. 1. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to step 9.
8. With ECM connector disconnected and MPI relay connector disconnected, ground fuel pump check terminal. Check resistance between chassis ground and ECM connector terminal No. 109, and between chassis ground and MPI relay connector terminal No. 1. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
9. With fuel pump connector and MPI relay connector disconnected, ground MPI relay connector terminal No. 1. Check for continuity between chassis ground and fuel pump connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
10. On all models, with MPI relay connector disconnected, check for continuity between chassis ground and MPI relay connector terminal No. 6. If continuity does not exist, repair wiring harness as necessary. If continuity exists, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.
11. Reconnect ECM connector and MPI relay connector. While cranking engine, check voltage between chassis ground and MPI connector terminal No. 1. Voltage should be 8 volts or more. Race engine. Voltage should be 12 volts or more. If voltage is not as specified, replace MPI relay. Repeat step 11. If voltage is still not as specified, replace ECM. If voltage is as specified, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 43: EGR TEMPERATURE SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to step 2. Remove EGR temperature sensor from intake manifold. Submerge temperature sensing portion of EGR temperature sensor in hot water. Using DVOM, check resistance across sensor terminals. Resistance should be 60,000-83,000 ohms at 122°F (50°C), 11,000-14,000 at 212°F (100°C). If resistance is not as specified, replace EGR temperature sensor. If resistance is as specified, go to step 3.
2. Warm engine to operating temperature. Allow engine to idle for 2 minutes. Squeeze green-striped hose between EGR valve and EGR solenoid. Using scan tester, read EGR temperature sensor temperature. At 700-750 RPM, scan tester should read 212°F (100°C) or less. AT 3500-4000 RPM, scan tester should read 248°F (120°C) or more. If reading is not as specified, replace EGR temperature sensor. If reading is as specified, go to next step.
3. Disconnect EGR temperature sensor connector. Using DVOM, check continuity between chassis ground and EGR temperature sensor terminal No. 1. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
4. On Stealth and 3000GT, go to next step. On all other models, with EGR temperature sensor disconnected, disconnect ECM connector. Check for continuity between EGR temperature sensor connector terminal No. 2 and ECM connector terminal No. 53. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
5. On all models, with EGR temperature sensor connector and ECM connector disconnected, turn ignition switch to ON position. Check voltage between chassis ground and EGR connector terminal No. 1. Voltage should be 3.3-4.7 volts. If voltage is not as specified on Stealth and 3000GT, repair wiring harness as necessary. If voltage is not as specified on all other models, replace ECM. If voltage is as specified, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODES 44, 52 & 53: IGNITION COILS

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Note. Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscilloscope.

Scheme 40

1. If using a scan tester, go to step 4. On Diamante, disconnect power transistor connector. Install Test Harness (MB991348) between transistor and connector. Start engine and accelerate to 1200 RPM. Using engine analyzer with oscilloscope capability, sequentially connect special pattern probe to ignition power transistor connector terminals No. 4 (coils No. 3 and 6), 5 (coils No. 2 and 5) and 6 (coils No. 1 and 4). (Scheme 40) Observe oscilloscope wave pattern at each terminal. Go to step 3.
2. On Stealth and 3000GT, start engine and let idle. Idle speed is 700 RPM for Stealth and 3000GT. Using engine analyzer with oscilloscope capability, connect special pattern probe at ignition power transistor terminal No. 13 for Stealth and 3000GT. Observe oscilloscope wave pattern. (Scheme 40) Connect special pattern probe at ignition power transistor terminal No. 3 for Stealth and 3000GT.
3. On all models, if oscilloscope wave pattern rise fluctuates to right and is between 2-4.5 volts for each transistor terminal, system is okay. If wave pattern is rectangular and is 2 volts or less, check for broken wire in primary ignition circuit. If wave pattern is rectangular and is 12 volts or more, replace defective ignition power transistor.
4. On all models, using scan tester, check for continuity between chassis ground and ignition timing adjustment terminal. With engine at idle, ground ignition timing adjustment terminal (located at fire wall). Scan tester should display ON. With ignition timing adjustment terminal not grounded, scan tester should display OFF. If conditions are not as specified, repair circuit between ignition timing adjustment connector and ECM terminal No. 104 on Stealth and 3000GT. If conditions are as specified, go to next step.
5. Connect timing light and tachometer. Ensure engine is at normal operating temperature. With engine at idle, 750 RPM for Diamante, or 700 RPM for Stealth and 3000GT, check ignition timing. Timing should be 7-23° BTDC for Diamante, Stealth and 3000GT.
6. With engine at 2000 RPM, timing should be 20-40° BTDC for Diamante, 30-50° BTDC on Stealth and 3000GT non-turbo models, or 23-43° BTDC on Stealth and 3000GT turbo models. Ground ignition timing adjustment terminal. On all models, with engine idling, ignition timing should be 3-7° BTDC.
7. On Diamante, disconnect ignition switch and ignition coil connectors. Using a DVOM, check for continuity between ignition switch connector terminal No. 4 and ignition coil connector terminal No. 3. If continuity does not exist, repair wiring between ignition switch and ignition coil. If continuity exists, go to next step.
8. Disconnect ignition power transistor connector. Check for continuity between power transistor connector terminal No. 9 and ignition coil connector terminal No. 3. If continuity does not exist, repair wiring between ignition power transistor and ignition coil. If continuity exists, go to next step.
9. Check for continuity between ignition power resistor connector terminal No. 1 and ignition coil connector terminal No. 4. Check for continuity between ignition power resistor connector terminal No. 2 and ignition coil connector terminal No. 1. Check for continuity between ignition power resistor connector terminal No. 3 and ignition coil connector terminal No. 2. If continuity does not exist, repair appropriate wiring between ignition power resistor connector and ignition coil connector. If continuity exists, go to next step.
10. Check for continuity between chassis ground and ignition coil connector terminals No. 1, 2 and 4. If continuity does not exist, check for short to ground between ignition power transistor and ignition coil. If continuity exists, go to next step.
11. On Stealth and 3000GT, disconnect ignition coil connector. Turn ignition switch to ON position. Using a DVOM, check voltage at ignition coil connector terminal No. 3. If battery voltage is not present, repair wiring between ignition coil and ignition switch. If battery voltage is present, go to next step.
12. Disconnect ignition power resistor connector. Check voltage at ignition power resistor connector terminal No. 6. If battery voltage is not present, repair wiring between ignition power resistor connector and ignition switch. If battery voltage is present, go to next step.
13. On all models, disconnect ECM connector. Ground ECM connector terminal No. 11 on Diamante, or No. 101 on Stealth and 3000GT. Check for continuity between chassis ground and ignition power transistor connector terminal No. 4 on Diamante, or terminal No. 5 on Stealth and 3000GT. On Diamante, ground ECM connector terminal No. 10. Check for continuity between chassis ground and ignition power transistor connector terminal No. 6. Ground ECM connector terminal No. 23. Check for continuity between chassis ground and ignition power transistor connector terminal No. 5.
14. Ground ECM connector terminal No. 101. Check for continuity between chassis ground and ignition power transistor connector terminal No. 8. On all models, if continuity does not exist, check appropriate circuit for open or short to ground between ignition power transistor and ECM. If continuity exists, go to next step.
15. Check for continuity between ignition power transistor connector terminal No. 1 and ignition coil connector terminal No. 4 on Diamante, or terminals No. 11 and 4 on Stealth and 3000GT. Check for continuity between ignition power resistor connector terminal No. 2 and ignition coil terminal No. 1 on Diamante, terminals No. 12 and 1 on Stealth and 3000GT.
16. Check for continuity between ignition power transistor connector terminal No. 3 and ignition coil connector terminal No. 2 on Diamante or terminals No. 13 and 2 on Stealth and 3000GT. If continuity does not exist, repair appropriate wiring between ignition power transistor and ignition coil. If continuity exists, go to next step.
17. Check for continuity between chassis ground and ignition power transistor connector terminal No. 7 on Diamante, or terminal No. 4 on Stealth and 3000GT. If continuity does not exist, repair wiring between ignition power transistor connector and ground. If continuity exists, go to next step.
18. With ignition switch in START position, check voltage at ignition power transistor connector terminals No. 4, 5 and 6 on Diamante, or terminals No. 1, 2 and 3 on Stealth and 3000GT. Voltage should be 0.5-4.0 volts. If voltage is not as specified, repair appropriate wiring between ignition power transistor connector and ECM connector terminals No. 10, 11 and 23 on Diamante, Stealth and 3000GT. If voltage is as specified, go to next step.
19. With ignition switch in ON position, check voltage at ignition timing adjustment connector. On all models, voltage should be 4-5.2 volts. If voltage is as specified, circuit is okay. If voltage is not as specified, repair wiring between ignition timing adjustment connector and ECM connector terminal No. 104 on Diamante, Stealth and 3000GT.

CODE 55: IDLE AIR CONTROL POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Manufacturer does not provide component testing procedure without using scan tester. Ensure engine coolant temperature is 185-205°F (85-95°C). Place transmission in Park or Neutral. Turn off all accessories except A/C. Ensure A/C clutch is operating when A/C system is on. Allow engine to idle.
2. Using scan tester, read Idle Air Control (IAC) position sensor step. See «IAC POSITION SENSOR STEP SPECIFICATIONS»(ref-18911-S25506527222001010800000) table. If scan tester does not read as specified, replace IAC position sensor. If readings are as specified, go to next step. IAC POSITION SENSOR STEP SPECIFICATIONS A/C Switch Position Standard Step Value Off 2-20 On Increase From 8-50 (1) Increase From 3-40 (1) For A/T models. Brakes applied, transmission selector in "D" and A/C on.
3. Disconnect ECM connector and IAC position sensor connector. Ground specified ECM connector terminal and using DVOM, check continuity between chassis ground and specified IAC connector terminal. See «ECM TO IAC HARNESS CIRCUIT ID»(ref-18911-S09951870992001010800000) table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step. ECM TO IAC HARNESS CIRCUIT ID Application ECM Terminal No. IAC Terminal No. All Models 5 4 18 2 61 1
4. With IAC position sensor connector disconnected, check continuity between chassis ground and IAC position sensor connector terminal No. 3. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
5. With IAC position sensor connector disconnected and ECM connector connected, turn ignition switch to ON position. Check for voltage between chassis ground and IAC connector terminals No. 2 and 4. If voltage is not 4.8-5.2 volts on either circuit, replace ECM. If voltage is as specified, go to next step.
6. Check voltage between chassis ground and IAC position sensor connector terminal No. 1. If voltage is not 4.8-5.2 volts, replace ECM. If voltage is as specified, condition required to set code is not present at this time. Test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 59: REAR OXYGEN (O2) SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. If using scan tester, go to next step. Disconnect O2 sensor connector. Using DVOM, check continuity between O2 sensor terminals. 3 and 4. If continuity does not exist, replace O2 sensor. If continuity exists, go to step 3.
2. With an assistant, road test vehicle. Drive vehicle with wide open throttle in 2nd gear (M/T) or "L" position (A/T). Using scan tester, read O2 sensor voltage. If O2 sensor voltage is not .6-1.0 volt at 3500 RPM, replace O2 sensor. If voltage is as specified, go to next step.
3. Disconnect O2 sensor connector and MPI relay connector. Using DVOM, check for continuity between O2 sensor connector terminal No. 3 and MPI relay connector No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
4. With O2 sensor connector disconnected, disconnect ECM connector. Check for continuity between O2 sensor connector terminal No. 1 and ECM connector terminal No. 55. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
5. With O2 sensor connector disconnected, check for continuity between chassis ground and O2 sensor connector terminals No. 2and 4. If continuity does not exist on either circuit, repair wiring harness as necessary. If continuity exists and preceding test procedure did not discover any faults, replace O2 sensor.

CODE 61: TRANSAXLE CONTROL MODULE SIGNAL

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

1. Disconnect Transaxle Control Module (TCM) and ECM connectors. Ground TCM connector terminal No. 7. Using DVOM, check continuity between chassis ground and ECM connector terminal No. 116. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
2. Ground TCM connector terminal No. 9. Check continuity between chassis ground and ECM connector terminal No. 59. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
3. Ground TCM connector terminal No. 108 to ground. Check continuity between chassis ground and ECM connector terminal No. 7. If continuity does not exist, repair wiring harness as necessary. If continuity exists, test is complete. Intermittent problem may exist. See «TESTS W/O CODES»(ref-18913) article.

CODE 62: INDUCTION CONTROL VALVE POSITION SENSOR

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article. Induction control valve position sensor is built into induction control motor.

1. Disconnect induction control motor connector and ECM connector. Ground ECM connector terminal No. 61. Using DVOM, check continuity between chassis ground and induction control motor connector terminal No. 1.
2. Ground ECM connector terminal No. 111. Check continuity between chassis ground and induction control motor connector terminal No. 2.
3. Ground ECM connector terminal No. 103. Check continuity between chassis ground and induction control motor connector terminal No. 4.
4. If continuity exists in previous steps, go to next step. If continuity does not exist in previous steps, check for open or short to ground in appropriate circuit between ECM connector and induction control motor.
5. With induction control motor connector disconnected, check continuity between chassis ground and induction control motor connector terminal No. 3. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
6. Turn ignition switch to ON position. Ensure control motor connector is disconnected and ECM connector is connected. Using DVOM, check voltage at induction control motor connector terminals No. 2 and 4. If voltage is not 4.8-5.2 volts, repair wiring harness as necessary. If wiring harness is okay, replace ECM. If voltage is as specified, go to next step.
7. Ensure ignition switch is in ON position. Ensure control motor connector is disconnected and ECM connector is connected. Using DVOM, check voltage at induction control motor connector terminal No. 1. If voltage is not 4.8-5.2 volts, repair wiring harness as necessary. If wiring harness is okay, replace ECM. If voltage is as specified, test is complete. Intermittent problem may exist. See appropriate «TESTS W/O CODES»(ref-18913) article. If wiring harness, connectors and induction control motor are okay, replace air intake plenum assembly. See «3.0L V6 - [H,J,K]»(ref-26423) article in ENGINES.

CODE 71: TRACTION CONTROL VACUUM SOLENOID

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Scheme 41

1. Turn ignition switch to ON position. Using a scan tester, actuate vacuum solenoid. With solenoid actuated, operating noise should be heard. If operating noise is not heard, go to next step. If operating noise is heard, go to step 4.
2. Disconnect vacuum solenoid and fuel injection relay connectors. Using DVOM, check for continuity between vacuum solenoid connector terminal No. 1 and fuel injection relay connector terminal No. 5. If continuity does not exist, repair wiring harness between fuel injection relay and vacuum solenoid as necessary. If continuity exists, go to next step.
3. Disconnect ECM connector. Ground ECM connector terminal No. 102. Check continuity between chassis ground and vacuum solenoid connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, check solenoid vacuum. Go to next step.
4. Remove vacuum hoses from solenoid. Ensure solenoid harness connector is disconnected. Connect a vacuum pump to solenoid nipple "A". Use jumper wires to connect battery voltage to solenoid terminals. (Scheme 41) With vacuum applied, nipple "B" unplugged, and negative jumper wire disconnected, solenoid should hold vacuum.
5. With vacuum applied, nipple "B" unplugged, and negative jumper wire connected, solenoid should not hold vacuum. With vacuum applied, nipple "B" plugged, and negative jumper wire connected, solenoid should hold vacuum.
6. If solenoid tests as described, check resistance between solenoid terminals. Resistance should be 36-44 ohms at 68°F (20°C). If resistance is not as specified, replace solenoid. If resistance is as specified, inspect throttle valve operation. Clean or repair as necessary.
7. Connect a vacuum pump to 90 degree vacuum nipple on vacuum tank. Apply 19.8" Hg of vacuum to tank and ensure vacuum holds. Connect vacuum pump to straight nipple on vacuum tank. Plug 90 degree nipple. Apply 19.8" Hg of vacuum. Unplug 90 degree nipple and ensure vacuum releases. Replace tank as necessary.
8. Remove Green stripe vacuum hose from vacuum actuator, located near throttle valve. Connect vacuum pump to actuator. With accelerator pedal depressed, apply 7.9" Hg of vacuum to actuator. Ensure actuator rod is pulled upward and vacuum is held. Repair actuator as necessary.

CODE 72: TRACTION CONTROL VENT SOLENOID

Note. For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article.

Scheme 42

1. Turn ignition switch to ON position. Using a scan tester, actuate ventilation solenoid. With solenoid actuated, operating noise should be heard. If operating noise is not heard, go to next step. If operating noise is heard, go to step 4.
2. Disconnect ventilation solenoid and fuel injection relay connectors. Using DVOM, check for continuity between ventilation solenoid connector terminal No. 1 and fuel injection relay connector terminal No. 5. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
3. Disconnect ECM connector. Ground ECM connector terminal No. 105. Check continuity between chassis ground and ventilation solenoid connector terminal No. 2. If continuity does not exist, repair wiring harness as necessary. If continuity exists, check solenoid vacuum. Go to next step.
4. Remove vacuum hoses from solenoid. Ensure solenoid harness connector is disconnected. Connect a vacuum pump to solenoid nipple "A". Use jumper wires to connect battery voltage to solenoid terminals. (Scheme 42) With vacuum applied, nipple "B" unplugged, and negative jumper wire connected, solenoid should hold vacuum.
5. With vacuum applied, nipple "B" unplugged, and negative jumper wire disconnected, solenoid should not hold vacuum. With vacuum applied, nipple "B" plugged, and negative jumper wire disconnected, solenoid should hold vacuum.
6. If solenoid tests as described, check resistance between solenoid terminals. If resistance is not 36-44 ohms at 68°F (20°C), replace solenoid. If resistance is as specified, go to «CODE 71: TRACTION CONTROL VACUUM SOLENOID»(ref-18911-S15277833992001010800000).

SUMMARY

If no hard fault codes (or only pass codes) are present, driveability symptoms exist, or intermittent codes exist, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.