Starting System: Diagnosis Chevrolet Silverado 1500 HD

TROUBLE SHOOTING

Note. For information not covered in this article, see STARTER - GENERAL TROUBLE SHOOTING .

Note condition and operation of SECURITY indicator light (if equipped). If SECURITY indicator light stays on or flashes continuously, repair anti-theft system as necessary. See THEFT DETERRENT . Check starter solenoid terminals and battery grounds. Check for proper installation of aftermarket electronic equipment. Check IGN-A (40-amp) fuse located in underhood fuse/relay center. Check CRANK (10-amp) fuse, located in instrument panel fuse block. If problem is found repair as necessary. If problem is not found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM .

DIAGNOSTIC STARTING POINT

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

1. The identification of the control module(s) which command the system.
2. The ability of the control module(s) 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 will identify the correct procedure for diagnosing the system and where the procedure is located.

ON-VEHICLE TESTING

Note. Before making electrical checks, visually inspect all terminals for clean, tight connections. Ensure all starting system related fuses are okay. Ensure battery is in good condition prior to testing starting system. Ensure charging system is okay. See GENERATORS & REGULATORS for Utility (SUV) models and GENERATORS & REGULATORS for Pickup models.

ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK

1. Did you perform the Battery Inspection/Test? If so, go to next step. If not, go to «BATTERY TESTING & INSPECTION (NON-HP2)»(ref-168656-S21569413602004111300000) .
2. Install a scan tool. Does the scan tool power up? If so, go to step 4 . If not, go to «SCAN TOOL DOES NOT POWER UP»(ref-180237-S20483619902005072400000) . NOTE: The engine may start during the following step. Turn off the engine as soon as you have observed the Crank power mode.
3. Access the Class 2 Power Mode in the Diagnostic Circuit Check on the scan tool. Rotate the ignition switch through OFF, RUN, and CRANK positions while observing the Class 2 Power Mode on the scan tool. Does the Class 2 Power Mode reading match the ignition switch positions for OFF, RUN and CRANK positions? If so, go to next step. If not, go to «POWER MODE MISMATCH»(ref-180243-S38832291102005072400000) .
4. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition. Turn ON the ignition, with the engine OFF. Attempt to communicate with each module on the Class 2 serial data circuit. If using a Tech 2, obtain this information using the Class 2 Message Monitor feature. Does the scan tool communicate with any module on the Class 2 serial data circuit? If so, go to next step. If not, go to «SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE»(ref-180237-S30096945032005072400000)
5. The symptom list in Symptoms will determine the correct diagnostic procedure to use. 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 so, go to next step. If not, go to «ENGINE ELECTRICAL SYMPTOMS»(ref-168656-S16713383322004111300000) .
6. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed. Does the scan tool display any DTC beginning with "U"? If so, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article. If not, go to next step.
7. Does the scan tool display any DTC beginning with "P"? If so, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article. If not, go to next step.
8. Does the scan tool display any DTC beginning with "B"? If so, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article. If not, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in in appropriate SELF-DIAGNOSTICS article .

BATTERY TESTING & INSPECTION (NON-HP2)

Note. The battery test using the Battery Tester (J-42000) requires correct connections to the battery terminals. A failure to obtain the correct connections during the test may result in a failed test on a good battery. Use the Out of Vehicle test for each battery when testing a vehicle with dual batteries.

Follow these instructions in order to avoid an incorrect diagnosis because of connections

1. If testing the vehicle with the battery cables still connected, wiggle the battery tester clips on the terminal bolt. This may cut through any coating or through any oxidation that may be present on the bolt. Even NEW bolts contain a protective coating that may insulate or cause a resistance in the test circuit.
2. If correct connections to the battery terminal bolts in the vehicle are in doubt, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the test adapters on the terminals. Follow the instructions for testing a removed battery.
3. If the tester displays a REPLACE BATTERY or BAD CELL-REPLACE result for a battery tested in the vehicle with the battery cables connected, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the tester adapters. NOTE: Always write the test code displayed by the tester on the repair order for any warranty purposes. The number is a unique code that describes the test data for a particular battery at a particular time. The test code may occasionally repeat when you retest the same battery. More often, each test will result in a different code. Use the test code from the second, or Out of Vehicle test. Follow the instructions for testing a removed battery. Replace the battery only if the second test shows a REPLACE BATTERY or BAD CELL-REPLACE result. Use the test code from the second test for any warranty purposes.
4. Use the correct terminal adapters. DO NOT use any common bolts or a combination of bolts, of nuts, and of washers as adapters when testing the battery. Use the test adapters that are provided with the battery tester or GM Terminal Adapters (12303040). If the adapters that are provided with the battery tester require replacement, use GM (12303040). Any other adapter may not contact the correct areas of the battery terminal, causing a resistance that may result in an invalid battery test result.

Note. Manufacturer recommends using Battery Tester (J-42000) for testing battery. Follow instructions provided with tester.

1. Inspect battery for a cracked, broken or damaged case. If battery is okay, go to next step. If battery case is not okay, go to step 19 .
2. Compare battery Cold Cranking Amperage (CCA) and Reserve Capacity (RC) to specifications. See «BATTERY SPECIFICATIONS»(ref-168656-S27524905702004111300000) table. If battery meets or exceeds specifications, go to next step. If battery does not meet or exceed specifications, go to step 19 . BATTERY SPECIFICATIONS Application Specification C/K Series (Pickup & Utility) Standard Replacement Battery Number 78-6YR Cold Cranking Amps 600 Amps Reserve Capacity 115 Minutes Optional Replacement Battery Number 78-7YR Cold Cranking Amps 770 Amps Reserve Capacity 115 Minutes Optional (Dual Batteries) GM Pt.# 19001814
3. Inspect battery hydrometer display. If hydrometer display shows a Yellow dot, go to next step. If hydrometer display does not show a Yellow dot, go to step 5 .
4. Using a small screwdriver, tap top of hydrometer display to dislodge any air bubbles inside. If hydrometer display still shows a Yellow dot, go to step 19 . If hydrometer display does not show a Yellow dot, go to next step.
5. Turn ignition switch off. Attempt to rotate negative battery cable connector clockwise with light finger pressure. If negative connector rotates, go to next step. If negative connector does not rotate, go to step 7 .
6. Use a torque wrench in order to verify the torque to loosen the negative battery terminal bolt. If torque is equal to or greater than specification, go to step 8 . If torque is less than specification, go to next step.
7. Disconnect negative battery cable and go to step 9 .
8. Disconnect negative battery cable. Inspect battery and cable terminals for corrosion and defects. Repair as necessary. Go to next step.
9. Attempt to rotate positive battery cable connector clockwise with light finger pressure. If battery cable rotates, go to next step. If battery cable does not rotate, go to step 11 .
10. Use a torque wrench in order to verify the torque to loosen the positive battery terminal bolt. If torque is equal to or greater than specification, go to step 12 . If torque is below specification, go to next step.
11. Disconnect positive battery cable and go to step 13 .
12. Disconnect positive battery cable. Inspect battery and cable terminals for corrosion and defects. Repair as necessary. Go to next step.
13. Clean and wire brush lead face of both battery terminals and metal contact surfaces on both cable connectors. Remove bolts from both battery cable connectors and inspect for corrosion and defects. Repair or replace as necessary. If battery and cables terminals are clean and in good condition, go to next step.
14. Connect positive battery cable to battery and tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-168656-S26794769732004111300000) . Go to next step.
15. Connect negative battery cable to battery and tighten bolt to specification. See «TORQUE SPECIFICATIONS»(ref-168656-S26794769732004111300000) . Go to next step.
16. Ensure all electrical loads are off. Follow manufacturers instructions and install Battery Tester (J-42000) to vehicle battery. Follow any instructions displayed on battery tester. If battery tester passed battery, go to next step. If battery tester did not pass battery, go to step 18 .
17. Press CODE button on battery tester. Record displayed code on vehicle repair order for warranty purposes. Did you complete this action? If so, battery is okay.
18. Press CODE button on battery tester. Record displayed code on vehicle repair order for warranty purposes. Replace battery.
19. Replace battery.

SELF-DIAGNOSTIC SYSTEM

Note. Diagnostic trouble code tests are written specifically for use with GM Tech I or Tech II scan tools. Generic scan tool can be used but may have limited functions. This article only covers the portion of those systems which relates to starting system diagnosis. For further information, see SELF-DIAGNOSTICS for appropriate system.

ENGINE ELECTRICAL SYMPTOMS

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

1. Perform «ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK»(ref-168656-S37217433932004111300000) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control module(s) can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to one of the following system operations: See «DESCRIPTION & OPERATION»(ref-168656-S15207831372004111300000) . See DESCRIPTION & OPERATION in «GENERATORS & REGULATORS»(ref-167946) .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the Starting and Charging Systems. See «CHECKING AFTERMARKET ACCESSORIES»(ref-168656-S35734129672004111300000) .
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. See «STARTER SOLENOID DOES NOT CLICK»(ref-168656-S12620526002004111300000) .
2. See «STARTER SOLENOID CLICKS, ENGINE DOES NOT CRANK»(ref-168656-S14597882072004111300000) .
3. See «ENGINE CRANKS SLOWLY»(ref-168656-S26258964712004111300000) .
4. See «BATTERY TESTING & INSPECTION (NON-HP2)»(ref-168656-S21569413602004111300000) .
5. See «STARTER MOTOR NOISE DIAGNOSIS»(ref-168656-S17905283222004111300000) .

Testing for Proper Terminal Contact

It is important to test terminal contact at the component and any in-line connectors before replacing a suspect component. Mating terminals must be inspected to ensure good terminal contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation.

Contamination may be caused by the connector halves being improperly connected. A missing or damaged connector seal, damage to the connector itself, or exposing the terminals to moisture and dirt can also cause contamination. Contamination, usually in the underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit.

Deformation is caused by probing the mating side of a connector terminal without the proper adapter. Always use the GM-approved terminal test kit when probing connectors. Other causes of terminal deformation are improperly joining the connector halves, or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact causing an open or intermittently open circuit.

STARTER MOTOR NOISE DIAGNOSIS

Diagnostic Aids

1. Inspect the flywheel ring gear for damage or unusual wear.
2. Shim the starter if applicable.
3. 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.

Refer to illustration for STARTER MOTOR NOISE DIAGNOSIS symptom test. (Scheme 1)

Scheme 1