Starting System: Diagnosis Pontiac Sunfire I

DIAGNOSTIC STARTING POINT (ENGINE ELECTRICAL)

Begin the system diagnosis with the DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL). See DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL) . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system.
2. The ability of the control modules to communicate through the serial data circuit.
3. The identification of any stored Diagnostic Trouble Codes (DTCs) and their status.

The use of the

DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)

will identify the correct procedure for diagnosing the system and where the procedure is located.

DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)

1. Perform the Battery Inspection/Test. See «BATTERY TESTING & INSPECTION»(ref-167574-S16492984082004101800000) . When complete, proceed to next step.
2. Install a scan tool. Turn on ignition, with engine off. Does the scan tool power up? If yes, proceed to next step. If no, see SCAN TOOL DOES NOT POWER UP in BODY CONTROL MODULES.
3. Turn on ignition, with engine off. Attempt to communicate with the Body Control Module (BCM), the Instrument Panel Cluster (IPC) and the Powertrain Control Module (PCM) on the class 2 serial data circuit. Does the scan tool communicate with all modules on the class 2 serial data circuit? If yes, proceed to next step. If no, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in BODY CONTROL MODULES.
4. Select the Display DTCs function for each module. If using a Tech 2, use the CLASS 2 DTC CHECK feature in order to determine which modules have DTCs set. Record all of the displayed DTCs, the DTC status, and the module which set the DTC. Does the scan tool display any DTCs? If yes, proceed to next step. If no, see «SYMPTOMS (ENGINE ELECTRICAL)»(ref-168596-S41178784062004111500000) .
5. Does the scan tool display any DTCs which begin with a "U"? If yes, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in BODY CONTROL MODULES. If no, proceed to next step.
6. Does the scan tool display DTCs B1000 or B1001? If so, go to BODY CONTROL MODULES.

SYMPTOMS (ENGINE ELECTRICAL)

Note. The following steps must be completed before using the symptom tables.

Perform DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL) before using the symptom tables in order to verify that there are no DTCs set and the control modules can communicate via the serial data link. Review the system description and operation in order to familiarize yourself with the system functions. See STARTING SYSTEM .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the starting and charging systems. See «CHECKING AFTERMARKET ACCESSORIES»(ref-168596-S02835128392004111500000) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «STARTER SOLENOID DOES NOT CLICK»(ref-168596-S30146945742004111500000)
2. «STARTER SOLENOID CLICKS, ENGINE DOES NOT CRANK»(ref-168596-S16831014302004111500000)
3. «ENGINE CRANKS SLOWLY»(ref-168596-S07788702052004111500000)
4. «STARTER MOTOR NOISE DIAGNOSIS»(ref-168596-S41868405492004111500000)

STARTER MOTOR NOISE DIAGNOSIS

Note. Inspect the flywheel ring gear for damage or unusual wear.

Note. Shim the starter as required.

Note. In order to add pinion to ring gear clearance a full size shim must be used. Do not shim only one starter mounting bolt. There are 3 shims available in different shapes, for clearance, all are 0.039" (1 mm) thick.

1. Did you perform the DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)? If yes, proceed to next step. If no, see «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(ref-168596-S40917223642004111200000) .
2. Start the engine. Does the starter operate normally? If yes, test for intermittent or poor conditions. If no, proceed to next step.
3. Start the engine while listening to the starter motor turn. Is there a loud "whoop" it may sound like a siren if the engine is revved while the starter is engaged after the engine starts, but while the starter is still held in the engaged position? If yes, go to step 6 . If no, proceed to next step.
4. Do you hear a "rumble", a "growl", or, in some cases, a "knock" as the starter is coasting down to a stop after starting the engine? If yes, go to step 7 . If no, proceed to next step.
5. When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally? If yes, go to step 8 . If no, go to step 7 .
6. Inspect the flywheel ring gear for chipped gear teeth, missing gear teeth or milled teeth. Is the flywheel bent, or does it have damaged teeth? If yes, go to step 9 . If no, go to step 10 .
7. Remove the starter motor. See «STARTER MOTOR»(ref-168596-S06417425402004111500000) . Inspect the starter motor bushings and clutch gear. Does the clutch gear have chipped or milled teeth or worn bushings? If yes, go to step 10 . If no, go to step 9 .
8. Shim the starter motor away from the flywheel by adding shims between the starter motor and the engine block one at a time. Flywheel runout may make this noise appear to be intermittent. When complete, go to step 11 .
9. Replace the flywheel. See ENGINE MECHANICAL. When complete, go to step 11 .
10. Replace the starter motor. See «STARTER MOTOR»(ref-168596-S06417425402004111500000) . When complete, proceed to next step.
11. Operate the system in order to verify the repair. Did you correct the condition? If yes, system is okay. If no, go to step 3 .

Circuit Description

When the ignition switch is placed in the START position 12 volts is supplied through the Park/Neutral Position (PNP) switch to the S terminal of the starter Solenoid. Ground is found through the engine block.