Battery Inspection/TEST
Battery Inspection/Test
12-Volt Battery
The following procedure is for the 12-Volt battery only.
Diagnostic Aids
Warning: Refer to Battery Disconnect Warning (Service Precautions).
Note: The 12V battery test using the J 42000 Battery Tester 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.
Follow these instructions in order to avoid an incorrect diagnosis because of connections:
* If testing the vehicle with the battery cables still connected, wiggle the J 42000 clips on the terminal. This may cut through any coating or through any oxidation that may be present on the terminal.
Even new bolts contain a protective coating that may insulate or cause a resistance in the test circuit.
* 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:
1. Disconnect the negative battery cable.
2. Disconnect the positive battery cable.
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.
3. Follow the instructions for testing a removed battery.
4. 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.
Reference Information
Schematic Reference
Starting and Charging Schematics (Electrical Diagrams)
Special Tools
J 42000 Battery Tester
Circuit/System Testing
Warning
Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
For Vehicles equipped with OnStar(R) (UE1) with Back Up Battery:
The Back Up Battery is a redundant power supply to allow limited OnStar(R) functionality in the event of a main vehicle battery power disruption to the VCIM (OnStar(R)module). Do not disconnect the main vehicle battery or remove the OnStar(R) fuse with the ignition key in any position other than OFF. Retained accessory power (RAP) should be allowed to time out or be disabled (simply opening the driver door should disable RAP) before disconnecting power. Disconnecting power to the OnStar(R) module in any way while the ignition is On or with RAP activated may cause activation of the OnStar(R) Back-Up Battery (BUB) system and will discharge and permanently damage the back-up battery. Once the Back-Up Battery is activated it will stay on until it has completely discharged. The BUB is not rechargeable and once activated the BUB must be replaced.
1. Inspect the 12V battery for a cracked, broken, or damaged case, which may be indicated by battery acid leakage.
• If there is any apparent damage, replace the battery.
2. Verify the cold cranking amperage (CCA), and reserve capacity (RC) and/or amp hour (AH) rating of the battery to the original battery or original equipment (OE) specification. Refer to Battery Usage ([1][2]Battery).
• If the 12V battery does not meet or exceed specifications, replace the battery.
3. Verify that the battery cables are clean and tight.
• If the battery cable(s) need to be cleaned, clean as required and connect the terminals.
• If the battery cable(s) are damaged, replace the cable(s).
4. Install the J 42000 and follow directions supplied by the tester.
• If the tester calls for charging the battery, refer to Battery Charging (Procedures).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Battery Positive Cable Replacement (Diesel) (Battery Positive Cable Replacement (Diesel))Battery Positive Cable Replacement (Gas) (Battery Positive Cable Replacement (Diesel))
* Battery Negative Cable Replacement (V6) (Service and Repair)Battery Negative Cable Replacement (V8) (Service and Repair)Battery Negative Cable Replacement (Diesel) (Service and Repair)
* Battery Replacement (Removal and Replacement)