AIR INDUCTION SYSTEMS
Note. Manufacturer does not provide testing procedures for many individual systems and components. For system and component testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. For location of components, see COMPONENT LOCATIONS .
SUPERCHARGER
For component testing, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
COMPUTERIZED ENGINE CONTROLS
Note. For location of components, see COMPONENT LOCATIONS .
PCM POWER & GROUND CHECK
Note. To identify circuits, see WIRING DIAGRAMS article.
Ground Circuits
- Using DVOM, check for continuity to ground at PCM ground terminals. (Схема №1) See WIRING DIAGRAMS article. Resistance should be zero ohms. If resistance is not zero ohms, repair open in ground circuit.
- Connect negative lead of DVOM to a known-good ground. Backprobe positive lead of voltmeter to each PCM ground terminal. With vehicle running, DVOM should indicate less than one volt. If DVOM reading is greater than one volt, check for open, short to voltage, corrosion or loose connection in ground circuit.
Power Circuits
- Using DVOM, check for battery voltage between PCM continuous power terminal(s) and ground. (Схема №1) See WIRING DIAGRAMS article. If battery voltage is not present, check for open fuse or fusible link. If fuse or fusible link is okay, check for open in circuit between PCM continuous power terminal and power source.
- Turn ignition switch to RUN position. Using DVOM, check for battery voltage between PCM ignition power terminals and ground. If battery voltage is not present, check IGN fuse. If fuse is okay, check for open in circuit between battery and ignition switch, and between ignition switch and PCM ignition power terminal. If circuits are okay, check for defective ignition switch.
- Connect DVOM between ground and PCM starter (crank) signal terminal. On vehicles with manual transmission/transaxle, depress clutch pedal. On vehicles with automatic transmission/transaxle, place gearshift lever in Park. On all vehicles, turn ignition switch to START position. Battery voltage should be present only when ignition switch is in START position.
- If voltage is not present, check CRANK fuse or fusible link between ignition switch and PCM starter (crank) signal terminal. If fuse or fusible link is okay, check for open in circuit between ignition switch and PCM starter (crank) signal terminal, or check for defective ignition switch.
SL Models
| Pin | Wire Color | Circuit No. | Function |
|---|---|---|---|
| 1 | DK BLU | 417 | Throttle Position Sensor - In |
| 2 | TAN | 472 | Air Temperature Sensor - In |
| 3 | LT GRN | 432 | Manifold Absolute Pressure Sensor - In |
| 4 | BRN | 1456 | Linear EGR - In |
| 5 | PPL/WHT | 1668 | Rear O2 - Hi - In |
| 6 | Not Used | ||
| 7 | DK BLU | 496 | Knock Sensor - In |
| 8 | YEL | 573 | Crank Position Sensor - 7X Hi - In |
| 9 | TAN | 413 | Front O2 - Lo - In |
| 10 | TAN | 413 | Rear O2 - Lo - In |
| 11 | GRY | 416 | Manifold Absolute Pressure Sensor - +5 Volts |
| 12 | BLK | 452 | Throttle Position Sensor - Return |
| 13 | WHT | 1579 | Oil Change Reset |
| 14 | Not Used | ||
| 15 | YEL | 772 | Selector Switch - B1 (Auto) |
| 16-17 | Not Used | ||
| 18 | PPL | 898 | Transaxle - 4th Out (Auto) |
| 19-21 | Not Used | ||
| 22 | BRN | 1295 | EVO - Lo |
| 23 | GRY | 416 | EGR + 5 Volts |
| 24 | Not Used | ||
| 25 | ORN/BLK | 586 | Transaxle Oil Temperature Sensor - In (Auto) |
| 26 | BRN/WHT | 633 | Camshaft Position - HI |
| 27 | PPL | 401 | Vehicle Speed Sensor - Lo |
| 28 | LT BLU | 1876 | Knock Sensor - Return |
| 29 | BLK | 452 | Air Temperature Sensor - Return |
| 30 | PPL | 574 | Crank Position Sensor - 7X Lo |
| 31 | BLK/WHT | 771 | Selector Switch - B0 (Auto) |
| 32 | BLK | 452 | Manifold Absolute Pressure Sensor - Return |
| 33 | DK BLU/WHT | 1231 | Turbine Speed Sensor - Lo (Auto) |
| 34 | YEL/BLK | 68 | Coolant Level |
| 35 | RED/BLK | 1230 | Turbine Speed Sensor - Hi (Auto) |
| 36 | WHT | 776 | Selector Switch - B3 (Auto) |
| 37-38 | Not Used | ||
| 39 | TAN/BLK | 422 | Transaxle - TCC Out (Auto) |
| 40 | LT GRN | 1222 | Transaxle - 2nd Out (Auto) |
| 41 | GRY | 474 | Throttle Position Sensor - + 5 Volts |
| 42 | LT GRN/BLK | 444 | Idle Air Control - B Lo - Out |
| 43 | LT BLU/BLK | 1748 | Idle Air Control - A Lo - Out |
| 44 | WHT | 1294 | EVO - Hi |
| 45 | LT GRN/WHT | 1749 | Idle Air Control - B Hi - Out |
| 46 | WHT | 423 | Electronic Ignition Module |
| 47 | Not Used | ||
| 48 | BLK | 452 | Coolant Temperature Sensor - Return |
| 49-50 | Not Used | ||
| 51 | TAN | 31 | Oil Pressure Sensor |
| 52 | GRY | 773 | Selector Switch - B2 (Auto) |
| 53 | BLK | 452 | Linear EGR - Return |
| 54 | YEL | 410 | Coolant Temperature Sensor In |
| 55 | TAN/WHT | 551 | Power Ground - Engine Ground Rear (Auto) |
| 56 | TAN/WHT | 551 | Power Ground - Engine Ground Rear |
| 57 | PNK/BLK | 1746 | Injector #3 |
| 58 | Not Used | ||
| 59 | YEL/BLK | 1223 | Transaxle - 3rd Out (Auto) |
| 60 | DK BLU | 1530 | Transaxle - Main Line Pressure - Out (Auto) |
| 61 | RED | 1676 | Linear EGR - Power |
| 62 | BRN/WHT | 25 | Generator |
| 63 | LT BLU | 697 | Linear EGR - Out |
| 64 | LT BLU/WHT | 1747 | Idle Air Control - A Hi - Out |
| 65 | ORN | 406 | Electronic Ignition Module - EST 2-3 Out |
| 66 | BLK | 452 | Transaxle Fluid Sensor - Temperature Return (Auto) |
| 67 | PNK/BLK | 429 | UHFB - Air Solenoid |
| 68 | DK GRN | 335 | UHFB - Cooling Fan Relay Control |
| 69 | Not Used | ||
| 70 | BRN | 436 | UHFB - Air Pump |
| 71 | PPL | 412 | Front Oxygen Sensor - Hi - In |
| 72 | YEL | 400 | Vehicle Speed Sensor - Hi - In |
| 73 | Not Used | ||
| 74 | DK GRN/WHT | 428 | Evaporator Emission Purge Solenoid - Out |
| 75 | BLK/WHT | 1423 | Heated O2 |
| 76 | TAN/WHT | 551 | Power Ground - Engine Ground Rear |
| 77 | TAN/WHT | 551 | Power Ground - Engine Ground Rear (Auto) |
| 78 | LT BLU/BLK | 844 | Injector #4 |
| 79 | BLK | 1744 | Injector #1 |
| 80 | LT GRN/BLK | 1745 | Injector #2 |
PCM CONNECTOR J1 TERMINAL IDENTIFICATION (1.9L)
| Pin | Wire Color | Circuit No. | Function |
|---|---|---|---|
| 1 | ORN | 1140 | UHFB - PCM B Fuse |
| 2 | GRY | 416 | I/P to Body Inline - Fuel Tank Pressure Sensor - + 5 Volt |
| 3 | GRY | 1884 | Roll Connector - Cruise Resume/Accel |
| 4-6 | Not Used | ||
| 7 | PPL | 30 | I/P to Body Inline - Fuel Level - In |
| 8 | GRN | 1140 | UHFB - PCM B Fuse |
| 9 | Not Used | ||
| 10 | DK GRN | 890 | I/P to Body Inline - Fuel Tank Pressure Sensor - In |
| 11 | PPL | 1807 | Cluster - Class 2 |
| 12 | PPL | 1807 | EBTCM - Class 2 (ABS)/Body Control Module - Class 2 (Non-ABS) |
| 13 | LT BLU | 1888 | Cruse Control Module - Cruse Clutch |
| 14 | WHT | 1310 | I/P to Body Inline - EVAP Emission Vent Solenoid - Out |
| 15 | ORN/BLK | 469 | IPFB - Fuel Tank Pressure Sensor - Return |
| 16 | Not Used | ||
| 17 | BLK/WHT | 251 | I/P to Body Inline - Fuel Level Return |
| 18 | Not Used | ||
| 19 | LT GRN | 1887 | Cruise Control Module |
| 20 | Not Used | ||
| 21 | GRY | 729 | UHFB - A/C Clutch Relay |
| 22 | Not Used | ||
| 23 | PNK | 439 | UHFB - Ignition |
| 24 | Not Used | ||
| 25 | DK GRN/WHT | 465 | IPFB - Fuel Pump |
| 26 | BRN | 86 | Brake Pedal Switch |
| 27 | Not Used | ||
| 28 | PNK | 1886 | Cruise Control Module |
PCM CONNECTOR J2 TERMINAL IDENTIFICATION (1.9L)
ENGINE SENSORS & SWITCHES
Note. For additional sensor testing specifications, see appropriate SENSOR OPERATING RANGE CHARTS article.
Note. Perform powertrain diagnostic system check prior to testing, and after completing any repairs. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article.
Manufacturer does not provide testing procedures for many individual systems and components. For sensor and switch testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. For location of components, see COMPONENT LOCATIONS .
2.2L (Cavalier & Sunfire) & 2.4L
Perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
3.1L (Lumina)
- Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing powertrain diagnostic system check, go to next step.
- Check for the following conditions: MAP sensor seal damaged or missing. Vacuum hoses disconnected, damaged or incorrectly routed. Intake manifold vacuum leaks. Vacuum leak at throttle body. Vacuum leaks in EGR system. Faulty PCV system. If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, go to step 14 .
- Disconnect MAP sensor harness connector. Turn ignition on, engine off. Using scan tool, observe MAP sensor parameter. If scan tool displays zero volts, go to next step. If scan tool does not display zero volts, go to step 12 .
- Connect a 3-amp fused jumper wire between MAP sensor signal circuit (Light Green wire) and MAP sensor reference voltage circuit (Gray wire) at MAP sensor harness connector. Turn ignition on, engine off. Observe MAP sensor parameter. If scan tool displays 4.95 volts, go to next step. If scan tool does not display 4.95 volts, go to step 8 .
- Using test light connected to battery voltage, probe MAP sensor signal circuit (Light Green wire) at MAP sensor harness connector. Observe MAP sensor parameter. If scan tool displays 4.95 volts, go to next step. If scan tool does not display 4.95 volts, go to step 9 .
- Turn ignition off. Check for faulty MAP sensor harness connections. If connections are okay, go to next step. If connections are not okay, repair as necessary. After repairs, go to step 14 .
- Check for open or high resistance in MAP sensor ground circuit (Orange/Black wire). If ground circuit is okay, go to step 11 . If ground circuit is not okay, repair as necessary. After repairs, go to step 14 .
- Check for open or high resistance in MAP sensor 5 volt reference circuit (Gray wire). If MAP sensor 5 volt reference circuit is okay, go to step 10 . If MAP sensor 5 volt reference circuit is not okay, repair as necessary. After repairs, go to step 14 .
- Check for open, short to ground or short to sensor ground circuit (Orange/Black wire) in MAP sensor signal circuit (Light Green wire). If MAP sensor signal circuit is okay, go to next step. If MAP sensor signal circuit is not okay, repair as necessary. After repairs, go to step 14 .
- Check for poor MAP sensor signal circuit connection at PCM. If connection at PCM is okay, go to next step. If connection at PCM is not okay, repair as necessary. After repairs, go to step 14 .
- Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Check for short to voltage in MAP sensor reference voltage circuit (Gray wire). If short to voltage does not exist, go to next step. If short to voltage exists, repair as necessary. After repairs, go to step 14 .
- Replace MAP sensor. If system is repaired, go to step 14 . If system is not repaired, go to next step.
- Replace PCM. After repairs, go to next step.
- Start engine and idle. While observing MAP sensor parameter on scan tool, increase engine RPM. If MAP sensor valve changes, system is okay. If MAP sensor valve does not change, go to step 2 .
3.1L (Except Lumina) 3.4L & 3.8L
- Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing powertrain diagnostic system check, go to next step.
- Install scan tool. Turn ignition on, engine off. Using scan tool, monitor and record MAP sensor kPa. MAP sensor value should be within 3 kPa of BARO. If MAP sensor value is normal for altitude, go to next step. If MAP sensor value is not normal for altitude, go to step 7 .
- Using scan tool, observe MAP sensor kPa display. Start engine. If MAP sensor value changes, go to next step. If MAP sensor value does not change, go to step 7 .
- Turn ignition off. Disconnect vacuum source from MAP sensor. Leave MAP sensor connected to engine harness. Connect hand vacuum pump to MAP sensor. Turn ignition on, engine off. Observe MAP sensor kPa and slowly apply vacuum one in. Hg at a time. Each one in. Hg of vacuum should result in 3-4 kPa drop in MAP sensor display. Observe MAP sensor display for skip or jump while increasing vacuum up to 20 in. Hg. If MAP sensor display for skips or jumps, go to step 13 . If MAP sensor display does not skip or jump, go to next step.
- Observe MAP sensor kPa display with 20 in. Hg of vacuum applied to sensor. If kPa display is less than 34 kPa, go to next step. If kPa display is 34 kPa or more, go to step 7 .
- Disconnect hand held vacuum pump. If MAP sensor display returns to value specified in step 2 , system is okay. If MAP sensor display does not return to value specified in step 2), go to step 13 .
- Turn ignition off. Disconnect MAP sensor harness connector. Turn ignition on, engine off. Using scan tool, observe MAP sensor voltage display. If more than zero volts exist, go to step 10 . If more than zero volts does not exist, go to step 8 .
- Using fused jumper wire, jumper MAP sensor 5-volt reference circuit (Gray wire) to MAP sensor signal circuit (Light Green wire). Using scan tool, observe MAP sensor voltage display. If MAP sensor voltage is 4.7-5.2 volts, go to next step. If MAP sensor voltage is not 4.7-5.2 volts, go to step 11 .
- Remove jumper wire. Using test light connected to battery voltage, probe MAP sensor ground circuit (Orange/Black wire). If test light illuminates, go to step 13 . If test light does not illuminate, go to step 12 .
- Check MAP sensor signal circuit (Light Green wire) for short to voltage. Repair as necessary. After repairs, go to step 2 . If circuit is okay, go to step 15 .
- Check MAP sensor 5-volt reference signal circuit (Gray wire) for high resistance. Repair as necessary. After repairs, go to step 2 . If circuit is okay, go to step 15 .
- Check MAP sensor ground circuit (Orange/Black wire) for high resistance. Repair as necessary. After repairs, go to step 2 . If circuit is okay, go to step 15 .
- Check MAP sensor connector for poor connection or terminal contact. Repair as necessary. After repairs, go to step 2 . If circuit is okay, go to next step.
- Replace MAP sensor. After repairs, go to step 2 .
- Inspect PCM for poor connection or terminal contact. Repair as necessary. After repairs, go to step 2 . If PCM connections are okay, go to next step.
- Replace PCM. After repairs, go to step 2 .
PARK NEUTRAL POSITION SWITCH
See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS for testing procedures.
MOTORS, RELAYS & SOLENOIDS
Note. Manufacturer does not provide testing procedures for many individual systems and components. For module, motor, relay and solenoid testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. For location of components, see COMPONENT LOCATIONS .
Idle Air Control (IAC) Motor
See IDLE CONTROL SYSTEM .
A/C Compressor Clutch Relay
See appropriate MANUAL A/C-HEATER SYSTEMS or AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
Fuel Pump Relay
Fuel pump relay is located in underhood fuse/relay block. To test fuel pump relay, see FUEL PUMP ELECTRICAL CIRCUIT under appropriate NO START - ENGINE CRANKS OKAY in appropriate BASIC DIAGNOSTIC PROCEDURES article.
SOLENOIDS
Note. Perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
FUEL SYSTEMS (GASOLINE)
| WARNING | ALWAYS release fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
Manufacturer does not provide testing procedures for many individual systems and components. For fuel system testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. Perform powertrain diagnostic system check prior to testing, and after completing any repairs. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article.
Note. For location of components, see COMPONENT LOCATIONS .
FUEL DELIVERY
Note. For fuel system pressure testing, see appropriate BASIC DIAGNOSTIC PROCEDURES article.
Fuel Pump Circuit
See FUEL PRESSURE under FUEL SYSTEMS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
Fuel Pressure Regulator
See FUEL PRESSURE under FUEL SYSTEMS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
FUEL CONTROL
Note. Retrieve DTCs and perform appropriate DTC test before performing FUEL INJECTOR CIRCUIT DIAGNOSIS. See appropriate SELF-DIAGNOSTICS article. Also, ensure all mechanical and ignition coil/module circuit malfunctions are repaired before performing fuel injector circuit diagnosis.
Fuel Pump Relay (Gasoline)
See RELAYS under MOTORS, RELAYS & SOLENOIDS.
FUEL SYSTEMS (2.2L - CAVALIER CNG)
Note. For location of components, see COMPONENT LOCATIONS .
IDLE CONTROL SYSTEMS
Note. For idle control system testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. Perform powertrain diagnostic system check prior to testing, and after completing any repairs. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article.
IGNITION SYSTEMS
Note. For basic ignition system checks, see appropriate BASIC DIAGNOSTIC PROCEDURES article.
Note. For ignition system testing, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
EMISSION SYSTEMS & SUBSYSTEMS
Note. For emission and subsystem testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Electric AIR Pump
Note. For electric AIR pump testing, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
EXHAUST GAS RECIRCULATION
| WARNING | Use protective gloves, or allow exhaust system to cool, before servicing exhaust system components. |
Note. Manufacturer does not provide testing procedures for many individual systems and components. For EGR system testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
Note. For EGR system diagnosis, see appropriate INSPECTION/MAINTENANCE PROCEDURES in appropriate SELF-DIAGNOSTICS article.
Exhaust System Check
- Remove heated oxygen sensor. Install exhaust backpressure tester in place of oxygen sensor. Start engine and let idle. If pressure reading is not 1.25 psi or greater, go to next step. If pressure reading is 1.25 psi or greater, go to step 3 .
- Increase engine speed to 2000 RPM. If pressure reading is greater than 3 psi, go to next step. If pressure reading is not greater than 3 psi, go to step 5 .
- Check exhaust system for crushed pipe, internal muffler damage or heat distress. If problem does not exist, go to next step. If problem exists, repair as necessary and go to step 5 .
- Replace catalytic converter. After repairs, go to next step.
- Operate vehicle within conditions under which original symptom was noted. If system operate properly, system is okay. If system does not operate properly, go to step 1 .
FUEL EVAPORATION
Note. Ensure all vacuum line and EVAP system components are not damaged or missing before proceeding with this test.
Required Service
The PCV system may require service for obstructions if any of the following conditions exist
- Rough idle.
- Stalling or slow idle speed.
- Oil leaks.
- Oil in air cleaner.
- Sludge in engine.
A leaking PCV valve or hose could cause
- Rough idle.
- Stalling.
- High idle speed.
If engine idles rough, check for clogged PCV valve, or plugged or broken hoses BEFORE adjusting idle. Check PCV valve application to ensure correct valve is fitted. Replace PCV valve if required.
Checking PCV Valve Function
- Disconnect PCV valve vacuum hose from cylinder head cover. Run engine at idle. Place thumb over open end of PCV valve vacuum hose to check for vacuum. If vacuum does not exist, check for obstruction in source vacuum supply. If source vacuum supply is okay, replace PCV valve.
- Turn ignition off. Remove PCV valve. Shake valve and listen for rattle of check valve inside PCV valve. If a clear rattle is not heard, replace PCV valve.
- Visually inspect valve for varnish or deposits which may make PCV valve operation sticky or restricted, or cause incomplete seating of valve. Replace as necessary.
- Engine must be sealed for PCV system to function as designed. If leakage, sludging or dilution of oil is noted and PCV system is functioning properly, check engine for cause and repair as required to ensure PCV system will continue to function properly.
- An engine operating without any crankcase ventilation can be damaged, so it is important to replace PCV valve and air cleaner breather (if equipped) at regular intervals (at least every 30,000 miles). Check all hoses and clamps for failure or deterioration.
MISCELLANEOUS CONTROLS
Note. Although some of the controlled devices listed here are not technically engine performance components, they can affect driveability if they malfunction.
Note. Manufacturer does not provide testing procedures for many individual systems and components. For system and component testing not listed, perform related DTC testing procedure. See appropriate SELF-DIAGNOSTICS article.
A/C COMPRESSOR CLUTCH CONTROLS
Note. For A/C compressor clutch circuit testing, see appropriate MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
ELECTRIC COOLING FAN
Note. For electric cooling fan circuit testing, see appropriate ELECTRIC COOLING FANS article in ENGINE COOLING.
TRANSMISSION
Note. For transmission electronic controls testing, see appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS. For component circuit identification, see WIRING DIAGRAMS article.