Engine Controls - Basic Diagnostic Procedures: Diagnosis Chevrolet Tracker II

VISUAL INSPECTION

Visually inspect all electrical wiring. Look for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and not pinched or cut. If necessary, see appropriate vacuum diagram in VACUUM DIAGRAMS article to verify routing and connections. Inspect air induction system for possible vacuum leaks.

NO-START DIAGNOSIS

Note. For terminal and circuit identification, see WIRING DIAGRAMS article.

1. Definition No-start is defined as engine cranks properly, but does not start. Engine may fire a few times.

Circuit Description

Battery voltage is supplied to ignition coils when ignition switch is turned to ON or START position. Ignition control module toggles primary winding of ignition coil in order to induce a high voltage in the secondary windings of ignition coil. PCM commands ignition control module based on numerous inputs, including camshaft position sensor. High voltage induced in secondary windings of ignition coil is applied through coil boots to spark plugs.

In order for engine to start and run, the correct amount of good quality fuel must be properly delivered to each cylinder. Timing of valve train operation in relation to piston position, and mechanical compression of air/fuel mixture are also critical.

1. Perform OBD system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
2. Check for DTCs. If DTC P0340 is set, diagnose using diagnostic procedure for DTC P0340. See appropriate SELF-DIAGNOSTICS article. If DTC P0340 is not set, go to next step.
3. Turn ignition on. Using scan tool, check data parameters of ECT, TP and MAP sensors. Locate and repair cause of any sensor reading that is not within expected value. After repairs, go to step 22 . If sensors are okay, go to next step.
4. Disconnect fuel injector harness connectors. Remove ignition coil No. 1. Install Spark Tester (J-26792) to each ignition coil spark plug boot, one wire at a time. Observe spark tester while cranking engine. If good spark exists at each plug boot, go to next step. If good spark does not exist at each plug boot, go to step 11 .
5. Turn ignition off. Install fuel pressure gauge. See «BASIC FUEL SYSTEM CHECKS»(ref-129529-S09305027702001111400000) . Turn ignition on. Fuel pump should run for about 2 seconds. It may be necessary to cycle ignition several times to obtain maximum pressure. Observe fuel pressure gauge while fuel pump is running. If fuel pressure is 36-43 psi (2.5-3.0 kg/cm 2 ), go to step 7 . If fuel pressure is not 36-43 psi (2.5-3.0 kg/cm 2 ), go to next step.
6. Turn ignition on. Fuel pump should run for about 2 seconds. Observe fuel pressure. If fuel pressure range is greater than 0-1 psi (0-0.7 kg/cm 2 ), diagnose fuel system. See «BASIC FUEL SYSTEM CHECKS»(ref-129529-S09305027702001111400000) . If fuel pressure range is less than 0-1 psi (0-0.7 kg/cm 2 ), diagnose fuel pump relay circuit. See «FUEL PUMP RELAY CIRCUIT DIAGNOSIS»(ref-129529-S27354273002001111400000) under BASIC FUEL SYSTEM CHECKS.
7. Check for contaminated fuel. If fuel is contaminated, repair as necessary. After repairs, go to step 22 . If fuel is okay, go to next step.
8. Check for fouled or incorrectly gapped spark plugs. Repair or replace as necessary. Attempt to start engine. If engine starts, go to step 22 . If engine does not start, go to next step.
9. Turn ignition off. Disconnect all 4 fuel injector harness connectors. Connect Fuel Injector Test Light (J-34730-2B) to each fuel injector harness connector, one connector at a time. Observe test light while cranking engine. If test light flashes for each injector, go to next step. If test light does not flash for each injector, diagnose fuel injector circuit. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article.
10. Check for faulty fuel injectors. See FUEL SYSTEM in appropriate SYSTEM & COMPONENT TESTING article. If injector is faulty, replace as necessary. After repairs, go to step 22 . If injectors are okay, go to step 21 .
11. Check ignition coils and spark plug boot for cracks, corrosion on terminals, carbon tracking and water intrusion. Repair or replace as necessary. After repairs, go to step 22 . If no problem is found, go to next step.
12. Disconnect electrical connector from ignition coil not supplying cylinders with spark. Turn ignition on. Connect test light between ground and ignition feed circuit of ignition coil (harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 16 .
13. Connect test light between battery positive and ground circuit of ignition coil (harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 15 .
14. Turn ignition off. Replace faulty ignition coil with known-good ignition coil. Install Spark Tester (J-26792) to each ignition coil spark plug boot, one wire at a time. Observe spark tester while cranking engine. If good spark exists at each plug boot, go to step 20 . If good spark does not exist at each plug boot, go to step 17 .
15. Repair open or poor connection in ignition coil ground circuit. After repairs, go to step 22 .
16. Repair open in ignition coil ignition feed circuit. After repairs, go to step 22 .
17. Check for open or short in ignition control circuit. Repair as necessary. After repairs, go to step 22 . If circuit is okay, go to next step.
18. Check for poor connection at PCM. Repair as necessary. After repairs, go to step 22 . If connection is okay, go to next step.
19. Replace PCM. Perform PCM relearn procedures. After repairs, go to step 22 .
20. Replace faulty ignition coil. After repairs, go to step 22 .
21. Check for the following engine mechanical conditions: Worn or faulty camshaft. Leaking or sticking valves. Leaking or sticking piston rings. Excessive valve deposits. Collapsed or sticking lifters. Weak valve springs. Incorrect valve timing. Leaking head gasket. Repair as necessary. After repairs, go to next step. If no problem is found, see «DIAGNOSTIC AIDS»(ref-129529-S07105860222001111400000) .
22. After repairs, start engine and observe Malfunction Indicator Light (MIL). If MIL illuminates for about 2 seconds, and then turns off, system is okay. If MIL does not illuminate or remains illuminated, diagnose MIL or check for DTCs. See appropriate SELF-DIAGNOSTICS article.

Diagnostic Aids

Check battery condition and engine cranking speed. Ensure starting system is operating properly to avoid misdiagnosis. Water or foreign material can cause a no-start condition during freezing weather. Low fuel pressure can result in a lean air/fuel mixture and may be difficult to ignite. Check for fouled or damaged spark plugs. Check for moisture on ignition system components. Check for a faulty main relay. Check camshaft position sensor signal circuit for Electromagnetic Interference (EMI) or poor connections. Check for open IG fuse (20-amp) located above lower left door hinge trim panel.

Check for intermittent condition which may be caused by poor connection, rubbed-through insulation, or broken wire inside its insulation. Check harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement. Repair as necessary.

Check for intermittent condition which may be caused by poor connection, rubbed-through insulation, or broken wire inside its insulation. Check harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement. Repair as necessary.

Powertrain Control Module (PCM) will energize fuel pump relay for 3 seconds when ignition is turned on. When fuel pump relay is energized, fuel pump will operate and pressurize fuel system. With engine cranking or running, PCM receives ignition system reference pulses and will continue to energize fuel pump relay.

1. Perform OBD system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
2. Remove fuel filler cap. Turn ignition on. Listen for fuel pump operation. Cycle ignition again if necessary. If fuel pump operates for about 2 seconds, go to next step. If fuel pump does not operate for about 2 seconds, go to step 4 .
3. Fuel pump electrical circuit is okay at this time. Check for intermittent problem. See appropriate TROUBLE SHOOTING - NO CODES article.
4. If fuel pump runs continuously with ignition on and engine off, go to step 17 . If fuel pump does not run continuously with ignition on and engine off, go to next step.
5. Turn ignition off. Remove fuel pump relay. Using test light connected to battery positive, probe fuel pump relay control circuit at relay cavity. Using scan tool, command fuel pump on. If test light illuminates, go to next step. If test light does not illuminate, go to step 16 .
6. Using test light connected to ground, probe fuel pump relay battery feed circuit (from main relay) at fuel pump relay cavity. Turn ignition on. If test light illuminates, go to next step. If test light does not illuminate, go to step 11 .
7. Turn ignition off. Connect fused jumper wire between fuel pump relay battery feed circuit (from main relay) and fuel pump relay load circuit (to fuel pump) at fuel pump relay cavities. Turn ignition on. If fuel pump runs, go to step 14 . If fuel pump does not run, go to next step.
8. Leave jumper wire connected. Using test light connected to ground, backprobe fuel pump power feed circuit at fuel pump harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 12 .
9. Turn ignition off. Remove jumper wire. Disconnect fuel pump harness connector. Using test light connected to battery positive, probe fuel pump ground circuit at fuel pump harness connector (harness side). If test light illuminates, go to next step. If test light does not illuminate, go to step 13 .
10. Remove fuel tank. Check fuel pump wire harness for damage. Remove fuel pump assembly. Check electrical connections and internal wire harness for damage. Repair as necessary. After repairs, go to step 24 . If no problem is found, go to step 22 .
11. Check for open in battery feed circuit between main relay and fuel pump relay. Repair as necessary. After repairs, go to step 24 . If circuit is okay, see «MAIN RELAY CIRCUIT DIAGNOSIS»(ref-129529-S14555553662001111400000) .
12. Repair open or high resistance in fuel pump power feed circuit between fuel pump relay and fuel pump harness connector. After repairs, go to step 24 .
13. Repair open or poor connection in fuel pump ground circuit. After repairs, go to step 24 .
14. Turn ignition off. Remove jumper wire. Turn ignition on. Using test light connected to ground, probe fuel pump relay ignition feed circuit (from IG fuse) at fuel pump relay cavity. If test light illuminates, go to step 21 . If test light does not illuminate, go to next step.
15. Repair open or short in fuel pump relay ignition feed circuit. After repairs, go to step 24 .
16. Check for open in fuel pump relay control circuit between fuel pump relay and PCM. Repair as necessary. After repairs, go to step 24 . If circuit is okay, go to step 23 .
17. Remove fuel pump relay. If fuel pump continues to run, go to next step. If fuel pump stops, go to step 19 .
18. Repair short to voltage in fuel pump power feed circuit. After repairs, go to step 24 .
19. Turn ignition off. Remove fuel pump relay. Using test light connected to battery positive, probe fuel pump relay control circuit at relay cavity. Turn ignition on and observe test light for 10 seconds. If test light remains illuminated for more than 3 seconds, go to next step. If test light does not remain illuminated for more than 3 seconds, go to step 21 .
20. Check for short to ground in fuel pump relay control circuit between fuel pump relay and PCM. Repair as necessary. After repairs, go to step 24 . If circuit is okay, go to step 23 .
21. Replace fuel pump relay. After repairs, go to step 24 .
22. Replace fuel pump. After repairs, go to step 24 .
23. Replace PCM. Perform PCM relearn procedures. After repairs, go to next step.
24. Operate vehicle under conditions which original symptom was noted. If system operates properly, system is okay. If system does not operate properly, see «DIAGNOSTIC AIDS»(ref-129529-S32155931562001111400000) .

Check for intermittent condition which may be caused by poor connection, rubbed-through insulation, or broken wire inside its insulation. Check harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement. Measure resistance of fuel pump relay coil. Resistance should be 79-95 ohms. Repair as necessary.

The main relay is controlled by PCM. The PCM provides a ground for the relay's coil anytime ignition is on. The main relay supplies ignition positive voltage to fuel pump relay, fuel injectors, MAF sensor, EVAP control system solenoids, EGR valve, IAC valve and PCM.

1. Perform OBD system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in appropriate SELF-DIAGNOSTICS article. After performing OBD system check, go to next step.
2. Check condition of FI fuse (15-amp) located in fuse block at right side of engine compartment, and IG fuse (20-amp) located in junction block. If either fuse is open, go to step 13 . If fuses are okay, go to next step.
3. Turn ignition on. Remove, and then reinstall main relay several times while listening for relay operation. If relay operates, see «DIAGNOSTIC AIDS»(ref-129529-S16003314272001111400000) . If relay does not operate, go to next step.
4. Turn ignition off. Remove main relay. Turn ignition on. Using test light connected to ground, probe main relay battery feed circuit (relay switch power) at relay cavity. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
5. Using test light connected to ground, probe main relay battery feed circuit (relay coil power) at relay cavity. If test light illuminates, go to next step. If test light does not illuminate, go to step 7 .
6. Turn ignition off. Using test light connected to battery positive, probe main relay control circuit at relay cavity. Turn ignition on. If test light illuminates, go to step 14 . If test light does not illuminate, go to step 8 .
7. Repair open in battery feed circuit between main relay and FI fuse. After repairs, go to step 16 .
8. Check for open in main relay control circuit between main relay and PCM. Repair as necessary. After repairs, go to step 16 . If circuit is okay, go to next step.
9. Using test light connected to ground, backprobe terminal No. 20 (ignition feed circuit) at PCM harness connector. If test light illuminates, go to step 11 . If test light does not illuminate, go to next step.
10. Repair open in ignition feed circuit between IG fuse and PCM. After repairs, go to step 16 .
11. Disconnect 26-pin and 30-pin PCM harness connectors. Using test light connected to battery positive, probe PCM ground circuits (Black/Blue wires and Black/Green wire) at PCM harness connectors. If test light illuminates for all circuits, go to step 15 . If test light does not illuminate for all circuits, go to next step.
12. Repair open in PCM ground circuit(s). After repairs, go to step 16 .
13. Repair short to ground in FI fuse circuit or IG fuse circuit. After repairs, go to step 16 .
14. Replace main relay. After repairs, go to step 16 .
15. Replace PCM. Perform PCM relearn procedures. After repairs, go to next step.
16. Operate vehicle under conditions which original symptom was noted. If system operates properly with no DTCs set, system is okay. If DTCs are set, diagnose using appropriate diagnostic procedure for DTC set. See appropriate SELF-DIAGNOSTICS article.

Check for intermittent condition which may be caused by poor connection, rubbed-through insulation, or broken wire inside its insulation. Check harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement. Measure resistance of main relay coil. Resistance should be 79-95 ohms. Repair as necessary.