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Starting System Buick Century VI

Starter 4 illustrations ~5408 words

IDENTIFICATION

Vehicle model is identified by fourth character of Vehicle Identification Number (VIN). The VIN is stamped on a metal pad on top of the left end if the instrument panel, near the windshield.

Body Code (1)Model
"W"Century
"W"Regal
(1) Body code is fourth character of VIN.
(1)Body code is fourth character of VIN.

MODEL IDENTIFICATION

DESCRIPTION & OPERATION

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

STARTER

The PG starter motors are non-repairable starter motor. They have pole pieces that are arranged around the armature. Both solenoid windings are energized. The pull-in winding circuit is completed to the ground through the starter motor. The windings work together magnetically to pull and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the engine. Moving at the same time, the plunger also closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding because battery voltage is applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine starts, pinion overrun protects the armature from excessive speed until the switch is opened.

When the ignition switch is released from the START position, the START relay opens and battery voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to the ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now opposite the direction of the current flow when the winding was first energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, causes the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter circuit is turned off.

Circuit Description

Moving the ignition switch to the Start position sends a 12-volt signal through the Crank Signal BCM, Cluster fuse in the I/P Fuse Block, to the BCM, IPC, and PCM to notify these modules that a crank status has been requested. At the same time 12 volts is fed through the PCM BCM U/H Relay fuse in the I/P Fuse Block to the coil side of the CRANK relay. The PCM grounds this circuit when all parameters are met for starting the engine. This closes the CRANK relay allowing Battery Positive voltage through the CRANK fuse and CRANK relay in the Underhood Fuse Block then through the Park/Neutral Position Switch to the S terminal of the starter solenoid. Ground is found through the engine block.

COMPONENT LOCATIONS

ComponentLocation
StarterLower Front Of The Engine Compartment
() To locate and identify starter and starter components (Scheme 1)and/or (Scheme 2).
()To locate and identify starter and starter components (Scheme 1)and/or (Scheme 2).

COMPONENT LOCATIONS

Scheme 1

Scheme 1
Scheme 1

Scheme 2

Scheme 2
Scheme 2

PROGRAMMING

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

POWERTRAIN CONTROL MODULE (PCM)

To program PCM for 3.1L engines, see POWERTRAIN CONTROL MODULE under PROGRAMMING in SELF-DIAGNOSTICS - 3.1L in FAULT ISOLATION under ENGINE PERFORMANCE. To program PCM for 3.8L engines, see POWERTRAIN CONTROL MODULE PROGRAMMING in SELF-DIAGNOSTICS - 3.8L in FAULT ISOLATION under ENGINE PERFORMANCE.

TROUBLE SHOOTING

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Note. Refer to wiring diagram to verify wire color and connector terminal identification. See WIRING DIAGRAMS .

PRELIMINARY INSPECTION

Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. For fuse and/or relay identification, see FUSES & CIRCUIT BREAKERS under ELECTRICAL.

Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM .

SELF-DIAGNOSTIC SYSTEM

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Using Scan Tool

DTCs are retrieved using a Tech 2(R) scan tool or other OBD-II compatible scan tool connected to OBD-II 16-pin Data Link Connector (DLC). DLC is located below left side of dash. If no DTC's exist, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

CLEARING DIAGNOSTIC TROUBLE CODES

There are 3 methods to clear DTCs.

Scan tool is preferable way to clear DTC information. Freeze frame and failure record data will also be cleared. PCM adaptive learning and system monitors will only be cleared for those system which had a stored DTC. A current DTC Last Test Failed clears when the diagnostic runs and passes.

Disconnecting Battery

Note. On many OBD-II systems, PCM will retain memory for an extended period of time with battery disconnected. Memory may be retained for several days.

Disconnecting PCM power or battery ground will clear all PCM memory including DTCs, freeze frame, failure records, adaptive learning and system monitors.

Warm-Up Cycles

The PCM uses warm-up cycles to run some diagnostics and to clear any Diagnostic Trouble Codes (DTCs). A warm-up cycle occurs when the engine coolant temperature increases 72°F (22°C) from the start-up temperature. The engine coolant must also achieve a minimum temperature of 160°F (71°C). The PCM counts the number of warm-up cycles in order to clear the Malfunction Indicator Light (MIL). The PCM will clear the DTCs when 40 consecutive warm-up cycles occur without a malfunction.

DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)

  1. Perform the Battery Inspection/Test. See «BATTERY TESTING & INSPECTION»(/buick/century/vi-1997-2005/remont/charging-system/#charging-system__battery-testing-inspection) under ON-VEHICLE TESTING in STARTING & CHARGING SYSTEMS under CHARGING SYSTEMS in ELECTRICAL. Does the battery pass the test? If so, go to step 2 .
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. Does the scan tool power up? If so, go to step 3 . If not, go to appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
  3. Access the Ignition Switch parameter in the body control module (BCM) inputs data display list. Rotate the ignition switch through all positions while observing the ignition switch power mode parameter. Does the ignition switch parameter reading match the ignition switch position for all switch positions? If so, go to step 4 . If not, go to appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
  4. Turn ON the ignition, with the engine OFF. Attempt to communicate with each of the following modules on the class 2 serial data circuit: Body Control Module (BCM), Instrument Panel Cluster (IPC) and Powertrain Control Module (PCM). Does the scan tool communicate with all modules on the class 2 serial data circuit? If so, go to step 5 . If not, go to appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT.
  5. Select the Display DTCs function for the BCM, IPC, and PCM. Record all of the displayed DTCs, the DTC status, and the module which set the DTC. Does the scan tool display any DTCs? If so, go to step 6 . If not, go to «SYMPTOM INDEX»(/buick/century/vi-1997-2005/remont/starter/#starting-system) table under SYSTEM TESTS.
  6. Does the scan tool display any DTCs which begin with a "U"? Go to appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. If not, go to step 7 .
  7. Does the scan tool display DTC B1000, B1004, B1007, or B1009? If so, go to appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. If not, go to «DIAGNOSTIC TESTS»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-tests) .

DIAGNOSTIC TESTS

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

The PCM monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect data input can occur when the voltage is out of range. The PCM monitors the system voltage over an extended length of time. If the PCM detects a system voltage outside an expected range for the calibrated length of time, DTC P0560 will set.

Conditions for Running the DTC

System voltage below 11 volts. Engine speed above 1500 RPM. Vehicle speed below 25 MPH.

Conditions for Setting the DTC

The PCM detects a system voltage out of range for 2 seconds.

Conditions for Clearing the DTC

The PCM will command the message OFF after one trip in which the diagnostic test has been run and passed. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. The DTC can be cleared by using the scan tool Clear DTC Information function.

Testing

  1. Did you perform the Engine Electrical Diagnostic System Check? If so, go to step 2 . If not, go to «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-system-check-engine-electrical) under SELF-DIAGNOSIS SYSTEM.
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. With a scan tool, observe the Ignition 1 Signal parameter in the PCM data list. Does the scan tool indicate that the Ignition 1 Signal parameter is greater than the specified range (11.0 volts)? If so, go to step 6 . If not, go to step 3 .
  3. Using a scan tool compare the Battery Voltage parameter in the DIM data list with the Ignition 1 Signal parameter in the PCM data list Is the battery voltage and PCM Ignition 1 readings different by more than the value specified (0.5 volts)? If so, go to step 4 . If not, go to «TEST A: CHARGING SYSTEM TEST»(/buick/century/vi-1997-2005/remont/charging-system/#charging-system) under SYSTEM TESTS in STARTING & CHARGING SYSTEMS.
  4. Test the battery positive voltage circuit of the PCM for a high resistance. Did you find and correct the condition? If so, go to step 7 . If not, go to step 5 .
  5. Inspect for poor connections at the harness connector of the PCM. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 7 . If not, go to step 6 .
  6. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(ref-159248-S03513737632003112000000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. After repairs are complete, go to step 7 .
  7. Review and record the scan tool Fail Records data. Use the scan tool in order to clear the DTC. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. See «CONDITIONS FOR RUNNING THE DTC»(/buick/century/vi-1997-2005/remont/starter/#starting-system__conditions-for-running-the-dtc) . Using the scan tool, observe the Specific DTC Information for DTC P0560 until the test runs. Does the scan tool indicate that DTC P0560 failed this ignition? If so, go to step 2 . If not, system OK.

The powertrain control module (PCM) uses the generator turn on signal circuit to control the generator. A high side driver within the PCM allows the PCM to turn the generator ON and OFF. When Generator operation is desired, the PCM sends a 5 volt signal to the voltage regulator via the generator turn ON signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the PCM, the voltage regulator controls generator output independently of the PCM. Under certain operating conditions, the PCM can turn OFF the generator by turning OFF the 5 volt signal on the generator turn ON signal circuit. The PCM has fault detection circuitry which monitors the state of the generator turn ON signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the PCM to set the DTC.

The PCM receives generator output or electrical load feedback via the generator field duty cycle signal circuit. The voltage regulator generates a PWM signal on the field control circuit. The regulator varies the pulse width of this signal in order to control generator output. This signal is also sent to the PCM via the generator field duty cycle signal circuit. The pulse width of the signal is proportional to generator output. The PCM expects generator output to be within a predetermined range under certain operating conditions. If the PCM detects that the PWM signal on the generator field duty cycle signal circuit is not within the expected range, this DTC will set. When this DTC sets, the PCM sends a class 2 serial data message to the IPC illuminating the Charge indicator lamp.

The engine is running.

The generator turn on signal circuit voltage is low while the PCM is commanding the generator on and the condition is present for more than 30 seconds. Or the generator field duty cycle signal PWM is less than 5 percent and the engine RPM is less than 2,500. If the conditions are present for more than 30 seconds the DTC will set.

Action Taken When the DTC Sets

The PCM stores the DTC information into memory when the diagnostic runs and fails. The malfunction indicator lamp (MIL) will not illuminate. The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the MIL/DTC

A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. The current DTC will clear when the diagnostic runs and does not fail. Use a scan tool in order to clear the MIL diagnostic trouble code.

  1. Did you perform the Engine Electrical Diagnostic System Check? If so, go to step 2 . If not, go to «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-system-check-engine-electrical) under SELF-DIAGNOSTIC SYSTEM.
  2. Install a scan tool. Start the engine. With a scan tool, monitor the DTC Information for DTC P0620 in Engine Controls. Does the scan tool indicate that DTC P0620 has passed? If so, testing for intermittent and poor connections in wiring systems. If not, go to step 3 .
  3. With a scan tool, command the GEN L-Terminal OFF and then ON. While commanding the GEN L-Terminal OFF and ON, observe the Ignition 1 Signal parameter. Does voltage change with each command? If so, go to step 6 . If no, go to step 4 .
  4. Turn ON the ignition, leaving the engine OFF. Disconnect the generator harness connector. Measure the voltage between the generator turn on signal circuit and ground. With a scan tool, command the GEN L-Terminal ON. Does the voltage measure near the specified value (5.0 volts)? If so, go to step 7 . If not, go to step 5 .
  5. Test the generator turn on signal circuit for a short or open. Did you find and correct the condition? If so, go to step 11 . If not, go to step 8 .
  6. Test the generator battery positive voltage sense circuit for a high resistance or open. Did you find and correct the condition? If so, go to step 11 . If not, go to step 7 .
  7. Inspect for poor connections at the harness connector of the generator. Did you find and correct the condition? If so, go to step 11 . If not, go to step 9 .
  8. Inspect for poor connections at the harness connector of the PCM. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
  9. Replace the Generator. See «GENERATOR»(/buick/century/vi-1997-2005/remont/charging-system/#charging-system) under REMOVAL & INSTALLATION in STARTING & CHARGING article in CHARGING SYSTEMS IN ELECTRICAL. After repairs are complete, go to step 11 .
  10. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(ref-159248-S03513737632003112000000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. After repairs are complete, go to step 11 .
  11. Review and record the scan tool Fail Records data. Clear any DTCs. Operate the vehicle within the Fail Records conditions as noted. Using a scan tool, monitor the specific DTC info for DTC P0620. Does the scan tool indicate that DTC P0620 has failed this ignition? If so, go to step 2 . If not, system OK.

SYSTEM TESTS

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Note. Starter relay is also be referred to as CRANK relay.

Note. The following tests assume that engine and battery are operating normally and are at normal operating temperature, battery is fully charged, there are no engine problems that would cause a no-start condition, and no diagnostic trouble codes are present.

SymptomPerform Test
Starter Solenoid Does Not ClickA
Starter Solenoid Clicks, Engine Does Not CrankB
Engine Cranks SlowlyC
Starter Motor Noise DiagnosisD

SYMPTOM INDEX

TEST A: STARTER SOLENOID DOES NOT CLICK

  1. Did you perform the Engine Electrical Diagnostic System Check? If so, go to step 2 . If not, go to «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-system-check-engine-electrical) under SELF-DIAGNOSTIC SYSTEM.
  2. Install a scan tool. Turn ON the ignition, with the engine OFF. With the scan tool, observe the IMS parameter in the transmission control module (TCM) data list. Verify that the range selector is correct in every range. Does the range selector match the scan tool data list display? If so, go to step 3 . If not, go to «TRANSAXLE GEARSHIFT LEVER DISPLAY INOPERATIVE OR DISPLAYS INCORRECT RANGE»(/buick/century/vi-1997-2005/remont/automatic-trans/#automatic-transaxle-diagnosis-4t65-e__transaxle-gearshift-lever-display-inoperative-or) under SYMPTOM TESTS in DIAGNOSIS-4T65-E article in AUTOMATIC TRANSMISSION under TRANSAXLE/TRANSMISSION.
  3. Turn the ignition to the START position. Does the engine crank? If so, test for intermittent and poor connections in wiring systems. If not, go to step 4 .
  4. With a scan tool, observe the Crank Request Signal parameter in the powertrain control module (PCM) data list. Turn the ignition switch to the START position. Does the scan tool display Yes? If so, go to step 5 . If not, go to step 15 .
  5. Install a scan tool. With a scan tool, observe the Starter Relay Command parameter in the PCM data list. Turn the ignition switch to the START position. Does the scan tool display Yes? If so, go to step 9 . If no, go to step 6 .
  6. With a scan tool, observe the Crank parameter in the body control module (BCM) data list. Turn the ignition switch to the START position. Does the scan tool display Yes? If so, go to step 7 . If not, go to step 16 .
  7. With a scan tool, observe the Security Lamp State parameter in the BCM data list. Turn the ignition switch to the START position. Does the scan tool display Off? If so, go to step 8 . If not, go to appropriate ANTI-THEFT SYSTEMS article in DOOR LOCKS & ANTI-THEFT.
  8. With a scan tool, observe the Crank parameter in the instrument panel cluster (IPC) data list. Turn the ignition switch to the START position. Does the scan tool display Yes? If so, go to step 9 . If not, go to step 17 .
  9. Turn the ignition to the START position. Does the CRANK relay click? If so, go to step 12 . If not, go to step 10 .
  10. Turn OFF the ignition. Disconnect the CRANK relay. Turn ON the ignition, with the Engine OFF. Connect a test lamp between the battery positive voltage circuit of the CRANK relay coil and a good ground. Does the test lamp illuminate? If so, go to step 11 . If not, go to step 21 .
  11. Connect a test lamp between the battery positive voltage circuit of the CRANK relay coil and the control circuit of the CRANK relay. Turn the ignition to the START position. Does the test lamp illuminate? If so, go to step 25 . If not, go to step 22 .
  12. Turn OFF the ignition. Disconnect the CRANK relay. Connect a test lamp between the battery positive voltage circuit of the CRANK relay switch circuit and a good ground. Does the test lamp illuminate? If so, go to step 13 . If not, go to step 31 .
  13. Connect a 40-amp fused jumper between the battery positive voltage circuit of the Starter relay switch circuit and the supply voltage circuit of the starter solenoid. Does the engine crank? If so, go to step 25 . If not, go to step 14 .
  14. Did the fuse in the jumper open? If so, go to step 23 . If not, go to step 24 .
  15. Turn OFF the ignition. Disconnect the PCM. Connect a test lamp between the crank voltage circuit of the PCM and a good ground. Turn the ignition to the Start position. Does the test lamp illuminate? If yes, go to step 26 . Go to Step 18 .
  16. Turn OFF the ignition. Disconnect the BCM. Connect a test lamp between the crank voltage circuit of the BCM and a good ground. Does the test lamp illuminate? If so, go to step 27 . If not, go to step 19 .
  17. Turn OFF the ignition. Disconnect the IPC. Connect a test lamp between the crank voltage circuit of the IPC and a good ground. Does the test lamp illuminate? If so, go to step 28 . If not, go to step 20 .
  18. Test the crank voltage circuit of the PCM for an open or high resistance. Did you find and correct the condition? If so, go to step 38 . If not, go to step 29 .
  19. Test the crank voltage circuit of the BCM for an open or high resistance. Did you find and correct the condition? If so, go to step 38 . If not, go to step 29 .
  20. Test the crank voltage circuit of the IPC for an open or high resistance. Did you find and correct the condition? If so, go to step 38 . If not, go to step 29 .
  21. Test the battery positive voltage circuit of the Starter relay coil for an open or high resistance. Did you find and correct the condition? If so, go to step 38 . If not, go to step 29 .
  22. Test the control circuit of the CRANK relay for an open, high resistance or short to battery voltage. Did you find and correct the condition? If so, go to step 38 . If not, go to step 26 .
  23. Test the supply voltage circuit of the starter solenoid for a short to ground. Did you find and correct the condition? If so, go to step 38 . If not, go to step 30 .
  24. Test the supply voltage circuit of the starter solenoid for an open or high resistance. Did you find and correct the condition? If so, go to step 38 . If not, go to step 30 .
  25. Inspect for poor connections at the CRANK relay. Did you find and correct the condition? If so, go to step 38 . If not, go to step 32 .
  26. Inspect for poor connection at the PCM harness connector. Did you find and correct the condition? If so, go to step 38 . If not, go to step 33 .
  27. Inspect for poor connection at the BCM harness connector. Did you find and correct the condition? If so, go to step 38 . If not, go to step 34 .
  28. Inspect for poor connection at the IPC harness connector. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 38 . If not, go to step 35 .
  29. Inspect for poor connections at the ignition switch harness connector. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 38 . If not, go to step 36 .
  30. Inspect for poor connections at the starter solenoid. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 38 . If not, go to step 37 .
  31. Repair the open or high resistance in the battery positive voltage circuit of the CRANK relay switch. Did you complete the repair? If so, go to step 38 .
  32. Replace the CRANK relay. See FUSES & CIRCUIT BREAKERS under ELECTRICAL. After repairs are complete, go to step 38 .
  33. Perform the set up procedures for the PCM. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(ref-159248-S03513737632003112000000) under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. After repairs are complete, go to step 38 .
  34. Replace the BCM. See appropriate BODY CONTROL MODULES article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. After repairs are complete, go to step 38 .
  35. Replace the Instrument Panel Cluster (IPC). See appropriate GAUGES & INSTRUMENT PANELS article. Did you complete the replacement? Go to Step 38 .
  36. Replace the ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. After repairs are complete, go to step 38 .
  37. Replace the starter motor. See «STARTER»(/buick/century/vi-1997-2005/remont/starter/#starting-system) under REMOVAL & INSTALLATION. After repairs are complete, go to step 38 .
  38. Operate the system for which the symptom occurred. Did you correct the condition? If so, system OK. If not, go to step 2 .

TEST B: STARTER SOLENOID CLICKS, ENGINE DOES NOT CRANK

  1. Did you perform the Engine Electrical Diagnostic System Check? If so, go to step 2 . If not, go to «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-system-check-engine-electrical) under SELF-DIAGNOSTIC SYSTEM.
  2. Turn the ignition to the START position. Did the starter solenoid click? If so, go to step 3 . If not, go to «TEST A: STARTER SOLENOID DOES NOT CLICK»(/buick/century/vi-1997-2005/remont/starter/#starting-system__test-a-starter-solenoid-does-not) .
  3. Inspect the engine and belt drive system for mechanical binding, such as a seized engine or generator. Does the engine move freely? If so, go to step 4 . If not, got to appropriate TROUBLE SHOOTING - NO CODES article in FAULT ISOLATION in ENGINE PERFORMANCE.
  4. Test the battery positive cable between the battery and the starter solenoid for high resistance. Did you find and correct the condition? If so, go to step 8 . If not, go to step 5 .
  5. Test the ground circuit between the battery and the starter motor for a high resistance. Did you find and correct the condition? If so, go to step 8 . If not, go to step 6 .
  6. Inspect for poor connections at the starter. Test for intermittent and poor connections and connector repairs in wiring systems. Did you find and correct the condition? If so, go to step 8 . If not, go to step 7 .
  7. Replace the starter. See «STARTER»(/buick/century/vi-1997-2005/remont/starter/#starting-system) under REMOVAL & INSTALLATION. After repairs are complete, go to step 8 .
  8. Operate the system for which the symptom occurred. Did you correct the condition? If so, system OK. If not, go to step 2 .

TEST C: ENGINE CRANKS SLOWLY

  1. Perform the Battery Inspection/Test. «BATTERY TESTING & INSPECTION»(/buick/century/vi-1997-2005/remont/charging-system/#charging-system__battery-testing-inspection) under ON-VEHICLE TESTING in STARTING & CHARGING SYSTEMS under ELECTRICAL.
  2. Inspect the wiring for damage. Inspect all connections to the starter motor, the solenoid, the battery, and all ground connections. Test for intermittent conditions and poor connections, and connector repairs in wiring systems.
  3. Verify that the engine is not seized.
  4. If the battery, the wiring, and the engine are functioning properly, and the engine continues to crank slowly, replace the starter motor. See «STARTER»(/buick/century/vi-1997-2005/remont/starter/#starting-system) under REMOVAL & INSTALLATION.

Diagnostic Aids

Inspect the flywheel ring gear for damage or unusual wear. Shim the starter as required. 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 for Engine Electrical? If so go to step 2 . If not, go to «DIAGNOSTIC SYSTEM CHECK (ENGINE ELECTRICAL)»(/buick/century/vi-1997-2005/remont/starter/#starting-system__diagnostic-system-check-engine-electrical) under SELF-DIAGNOSTIC SYSTEM.
  2. Start the engine. Does the starter operate normally? If yes, testing for intermittent and poor connections in wiring systems. If not, go to step 3 .
  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 so, go to step 6 . If not, go to step 4 .
  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 so, go to step 7 . If not, go to step 5 .
  5. When the engine is cranked, do you hear a high-pitched whine after the engine cranks and starts normally? If so, go to step 8 . If not, 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 so, go to step 9 . If not, go to step 10 .
  7. Remove the starter motor. See «STARTER»(/buick/century/vi-1997-2005/remont/starter/#starting-system) under REMOVAL & INSTALLATION. Inspect the starter motor bushings and clutch gear. Does the clutch gear have chipped or milled teeth or worn bushings? If so, go to step 10 . If not, 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. Did you complete the repair? If so, go to step 11 .
  9. Replace the flywheel. Refer to Engine Flywheel Replacement in Engine Mechanical - 3.1L or Engine Flywheel Replacement in Engine Mechanical - 3.8L. See appropriate REMOVAL & INSTALLATION - A/T article in TRANSAXLE/TRANSMISSION. After repairs are complete, go to step 11 .
  10. Replace the starter motor. See «STARTER»(/buick/century/vi-1997-2005/remont/starter/#starting-system) under REMOVAL & INSTALLATION. After repairs are complete, go to step 11 .
  11. Operate the system in order to verify the repair. Did you correct the condition? If so, system OK. If not, go to step 3 .

REMOVAL & INSTALLATION

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG DEACTIVATION PROCEDURES under RESTRAINTS in GENERAL INFORMATION article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

Note. Vehicles are designed for starter mounting without shims. A single shim or double shims may have been added to correct a noise or engagement condition. Clearance shims .039" (1.0 mm) thick are available in 3 different shapes. When installing starter, any previously installed shims should be replaced in original location to ensure proper pinion to flywheel clearance.

Note. Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. DO NOT use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Removal (3.1L & 3.8L)

To identify and locate starter motor components (Scheme 1)and (Scheme 2).

  1. Disconnect the negative battery cable. Raise and support the vehicle. Remove the front lower air deflector panel. Remove the torque converter covers. Remove the starter solenoid BAT terminal nut and remove the positive battery cable from the starter motor.
  2. Remove the starter solenoid "S" terminal nut and remove the starter solenoid wire from the starter motor. Remove the starter bolts and the starter motor. (Scheme 3)
  3. Align the starter motor to the engine. Install the starter bolts finger tight until seated. Tighten the starter bolts to specification. See «TORQUE SPECIFICATIONS»(/buick/century/vi-1997-2005/remont/starter/#starting-system__torque-specifications).
  4. Install the positive battery cable and the solenoid BAT terminal nut. Tighten finger tight to the starter motor. Install the starter solenoid wire and the starter solenoid S terminal nut. Tighten finger tight to the starter motor. Tighten the solenoid BAT terminal nut to specification.
  5. Tighten the starter solenoid "S" terminal nut to specification. Install the torque converter covers. Install the front lower air deflector panel. Lower the vehicle. Connect the negative battery cable.

Scheme 3

Scheme 3
Scheme 3

OVERHAUL

Note. Starter assemblies are not serviceable and should be replaced as complete units.

STARTER SPECIFICATIONS

See STARTER MOTOR under STARTING in SPECIFICATIONS under SPECIFICATIONS INDEX in GENERAL INFORMATION.

TORQUE SPECIFICATIONS

ApplicationFt. Lbs. (N.m)
Starter Mounting Bolts32 (43)
INCH Lbs. (N.m)
Solenoid BAT Terminal Nut89 (10)
Solenoid "S" Terminal Nut27 (3)

TORQUE SPECIFICATIONS

CONNECTOR IDENTIFICATION

To identify starter connectors (Scheme 4)

Scheme 4

Scheme 4: CONNECTOR IDENTIFICATION
Scheme 4: CONNECTOR IDENTIFICATION

WIRING DIAGRAMS

For wiring, see article in SYSTEM WIRING DIAGRAMS in ELECTRICAL.