Proactive Alert Identifier SAC004

Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis Diagnostic Procedure Instructions for an overview of the diagnostic approach. Proactive Alert Identifier Descriptor Proactive Alert Identifier  Service Message Identifier SAC004 Predicted Starting and Charging — Low Cranking Capability Due to High Resistance in Starter System Conditions for Running the Proactive Alert Identifier Service message present. Conditions for Setting the Proactive Alert Identifier Low Cranking Capability Due to High Resistance in Starter System. Diagnostic Aids Proactive Alerts can be verified using the scan tool “Vehicle Diagnostics” » “Vehicle Proactive Alerts”, if the customer does not have the OnStar notification with them. No other action is required as the Proactive Alert Message will automatically clear once the system is repaired. The Proactive alert can be cleared with the scan tool if desired. Other on board DTCs may have set if the vehicle experienced a low voltage conditions. Use the scan tool to clear ALL DTCs prior to releasing the vehicle to the Customer. Reference Information Schematic Reference Starting and Charging Schematics Description and Operation Proactive Alerts Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Special Tools Equivalent regional tools: Special Tools Circuit/System Verification

Note

If the concern is still present after following the steps for Diagnostics in any of the Proactive Alert Identifiers, contact GM TAC for further assistance. The GM TAC Agent will arrange for the stuck Proactive Alert to be cleared from OnStar Back Office.

1. Verify the battery cable connections are clean and tight and verify battery voltage is between 12.0–15.0 V measured at the battery terminals. ⇒ If not within the specified range Refer to Battery Inspection/Test ⇓ If within the specified range
2. Verify the customer has the Proactive Alert SAC004 from OnStar, or by using the Scan Tool “Vehicle Diagnostics” » “Vehicle Proactive Alerts”, or Service Workbench Alerts. ⇒ If Proactive Alert SAC004 is present. Refer to Circuit/System Testing. ⇓ If Proactive Alert SAC004 is not present.
3. All OK. Circuit/System Testing
4. Test for the following values at each test location: Test for less than the 500 mV drop between the C1 Battery Positive Post and the X50D  Fuse Block—Battery with the ignition in CRANK/START. Test for less than 500 mV drop between X50D Fuse Block—Battery and terminal A X2 at the M64 Starter Motor with the ignition in CRANK/START. Test for less than 500 mV drop between negative battery cable and the M64 Starter Motor Case with the ignition in CRANK/START. ⇒ If 500 mV or greater between the C1 Battery Positive Post and the X50D Fuse Block— Battery Replace the X50D Fuse Block—Battery and continue testing voltage drop at all other cables. ⇒ If 500 mV or greater between at the X50D Fuse Block—Battery and terminal A X2 at the M64 Starter Motor Replace the battery starter cable between the X50D Fuse Block—Battery and M64 Starter Motor and continue testing voltage drop at all other cables. ⇒ If 500 mV or greater between negative battery cable and the M64 Starter Motor Case Replace the Battery Negative Cable. and continue testing voltage drop at all other cables.
5. Clear the Proactive Alert Using the Scan Tool “Vehicle Diagnostics” » “Vehicle Proactive Alerts”. ⇓ If all tests are less than the specific value
6. Replace the M64 Starter Motor.
7. Clear the Proactive Alert Using the Scan Tool “Vehicle Diagnostics” » “Vehicle Proactive Alerts”. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Battery Positive and Negative Cable Strap Replacement Starter Replacement Starter Solenoid Cable Replacement Engine Wiring Harness Junction Block Replacement