Starting System: Other GMC Envoy I

SLOW OR NO CRANK AFTER EXTENDED PERIODS OF VEHICLE NON-USE

There may be a parasitic load on electrical system. See PARASITIC LOAD EXPLANATION & TEST PROCEDURES article in GENERAL INFORMATION section.

ENGINE DOES NOT CRANK, STARTER SOLENOID DOES NOT CLICK

1. Place gear selector in Park (A/T) or depress clutch pedal (M/T). Place ignition switch to START position. Using DVOM, measure voltage between starter solenoid connector terminal "S" (Purple wire) and engine ground. If voltage is 12 volts or more, go to step 13). If voltage is less than 12 volts, go to next step.
2. Remove starter relay from Underhood Bussed Electrical Center (UBEC). See «COMPONENT LOCATIONS»(ref-33553-S40582010192001011700000) table. Connect a test light between starter relay socket terminal No. 30 (Red wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 14).
3. Disconnect Purple wire from starter solenoid terminal "S". Connect a test light between Purple wire and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 15).
4. Reconnect Purple wire to starter solenoid terminal "S". Connect a test light between starter relay socket terminal No. 86 (Black wire) and ground. If test light illuminates, go to next step. If test light does not illuminate, go to step 16).
5. Place gear selector in Park (A/T) or depress clutch pedal (M/T). Place ignition switch to START position. Using DVOM, measure voltage between starter relay socket terminal No. 85 (Purple/White wire) and engine ground. If voltage is 12 volts or more, go to next step. If voltage is less than 12 volts, go to step 17).
6. If vehicle is equipped with a manual transmission, go to next step. If vehicle is equipped with an automatic transmission, go to step 9).
7. Disconnect Clutch Pedal Position (CPP) switch connector. Turn ignition switch to START position. Using DVOM, check voltage between CPP switch wiring harness connector cavity "A" (Purple wire) and ground. If voltage is more than 12 volts, go to next step. If voltage is 12 volts or less, go to step 11).
8. Connect a fused jumper wire across CPP switch wiring harness connector cavities "A" (Purple wire) and "C" (Purple/White wire). Depress clutch pedal. Turn ignition switch to START. If starter cranks engine, go to step 18). If starter does not crank engine, go to step 19).
9. Disconnect Transmission Range (TR) switch connector. Turn ignition switch to START position. Using DVOM, check voltage between TR switch wiring harness connector C1 terminal "E" (Purple wire) and ground. If voltage is more than 12 volts, go to next step. If voltage is 12 volts or less, go to step 11).
10. Connect a fused jumper wire across TR switch wiring harness connector cavities "E" (Purple wire) and "G" (Purple/White wire). Turn ignition switch to START. If starter cranks engine, go to step 20). If starter does not crank engine, go to step 21).
11. Turn ignition switch to START. Check voltage between ignition switch connector C211 cavity D1 and ground. (Scheme 6) If voltage is more than 12 volts, go to step 22). If voltage is 12 volts or less, go to next step.
12. Check voltage between ignition switch connector C211 cavity D5 and ground. If voltage is more than 12 volts, go to step 23). If voltage is 12 volts or less, go to step 24).
13. Clean starter motor mounting bolts, starter motor and mounting surface, and repeat test. If starter still does not operate, replace starter.
14. Reinstall starter relay. Repair open in Red wire between starter relay and fuse "A" (40-amp) in underhood bussed electrical center. Recheck system.
15. Reinstall starter relay. Repair open in Purple wire between starter relay and starter solenoid. Recheck system.
16. Reinstall starter relay. Repair open in Black wire between starter relay and ground. Recheck system.
17. Replace starter relay. Recheck system.
18. Adjust CPP switch. Repeat test. If starter does not crank engine, replace CPP switch. Recheck system.
19. Repair open in Purple wire between starter relay and CPP switch. Recheck system.
20. Replace TR switch. Recheck system.
21. Repair open in Purple wire between starter relay and TR switch. Recheck system.
22. Check for open in Yellow wire between ignition switch and underhood bussed electrical center connector C1 terminal D3. Repair as needed. If circuit is okay, repair open in Purple wire between TR switch terminal "E" and underhood bussed electrical center connector C2 terminal F5 (A/T) or CPP switch terminal "A" and underhood bussed electrical center connector C1 terminal C3 (M/T). Recheck system.
23. Replace ignition switch. Recheck system.
24. Repair open in Orange wire between ignition switch and underhood bussed electrical center. Recheck system.

Scheme 6

SOLENOID CLICKS, ENGINE DOES NOT CRANK

1. Remove 20-amp ECM IGN fuse No. 10 from instrument panel fuse block. Turn ignition switch to START position and hold for 15 seconds. Using a DVOM, measure voltage between battery negative and positive terminals. If voltage is more than 9.5 volts, go to next step. If voltage is less 9.5 volts or less, perform battery load test. If battery is okay, go to next step. If battery fails load test, replace battery and recheck system.
2. Turn ignition switch to START position. Using a DVOM, measure voltage between battery negative terminal and engine ground. If voltage is more than .5 volt, repair or replace negative battery cable or connections. Recheck system. If voltage is .5 volt or less, go to next step.
3. Turn ignition switch to START position. Using a DVOM, measure voltage between battery positive terminal and starter solenoid terminal "B". If voltage is more than .5 volt, replace positive battery cable. If voltage is .5 volt or less, clean starter motor mounting blots, starter motor and mounting surface, and repeat test. If starter still does not engage, replace starter and recheck system.

PRELIMINARY TESTS

Note. On PG260 starter motor, starter is serviced as an assembly. If test values do not meet specifications, replace starter and solenoid as an assembly.

Remove starter from vehicle. See STARTER under REMOVAL & INSTALLATION . Check starter for damage such as broken or stripped electrical terminals, broken or cracked drive end housing. If no obvious damage is found, perform starter no-load test and pinion clearance check before disassembling starter motor.

SOLENOID WINDINGS TESTS

Note. To prevent overheating, DO NOT allow solenoid pull-in current to flow for more than 15 seconds.

Note. Current flow will decrease as windings heat up.

Hold-In Windings Test

1. If solenoid is not removed from starter motor assembly, disconnect field lead from terminal "M" on solenoid and insulate field lead from solenoid motor terminal. Connect an ammeter and switch in series with 12-volt battery and starter solenoid terminal "S" as illustrated. (Scheme 7) Connect a voltmeter between solenoid terminal "S" and ground. Connect a carbon pile across battery.
2. Turn switch on and quickly adjust carbon pile load until voltage reads as specified. Check ammeter reading. Turn off carbon pile and open switch. At 10 volts reading should be 10-20 amps. If amperage reading is not as specified, replace starter solenoid.

Pull-In Windings Test

Connect test equipment as in hold-in windings test. See HOLD-IN WINDINGS TEST. (Scheme 7) Ground starter solenoid terminal "M". Turn switch on and quickly adjust carbon pile load until voltage reads as specified. Check ammeter reading. Turn off carbon pile and open switch. At 10 volts reading should be 60-85 amps. If ammeter reading is not as specified, replace starter solenoid.

Scheme 7

BRUSHES, SPRINGS & HOLDERS CHECK

If any brushes are damaged (oil-soaked or pitted) or worn more than 90 percent, replace frame and fields. If brushes are not damaged and still have more than 50 percent of brush material left, use a soft cloth to clean contact face of brushes. Check brush spring tension and replace springs if weak, discolored or distorted. Ensure brush holders are clean and brushes are not binding in holders. Ensure full surface of brush contacts commutator for proper performance.

COMMUTATOR END FRAME & BEARING

Replace armature assembly if commutator outer diameter is less than 1.378" (36 mm) or if undercut depth is less than .008" (.2 mm). DO NOT undercut insulation. Ensure commutator end bearing has not spun in frame. If bearing has spun, replace frame and bearing. DO NOT lubricate bearing. If bearing is dry or damaged, replace bearing. Measure original bearing depth and install new bearing to same depth.

DRIVE END HOUSING & BEARING

Ensure drive end bearing has not spun in housing. If bearing has spun, replace housing and bearing. DO NOT lubricate bearing. If bearing is dry or damaged, replace bearing. Measure original bearing depth and install new bearing to same depth.

PINION CLEARANCE CHECK

Note. Pinion clearance is not adjustable. If clearance is not within specification, disassemble and check starter motor for worn or damaged components.

1. Secure starter motor in vise with opening in housing accessible for measurement. Disconnect field lead at solenoid terminal "M" and insulate from solenoid field terminal "M". Connect battery negative terminal lead to starter frame. Connect 12 volts to starter solenoid terminal "S". Momentarily touch jumper lead from starter solenoid terminal "M" to starter frame, shifting pinion into cranking position.
2. Push pinion as far as possible away from retainer. Using a feeler gauge, ensure there is.010-.160" (.25-4.06 mm) clearance between pinion and retainer. (Scheme 8)

Scheme 8

STARTER & SOLENOID

Note. When reassembling starter and solenoid, use Grease (10477431) for lubrication. Use of other greases may cause starter failure. Use illustrations for overhaul procedure. (Scheme 9)-11.

Note. On PG260 starter motor, starter and solenoid are not overhauled and are replaced as a complete assembly.

Scheme 9

Scheme 10

Scheme 11