Battery Inspection/Test
Battery Inspection/Test
Diagnostic Aids
Warning: Refer to Battery Disconnect Warning (Service Precautions).
Note:
* The battery test using the EL 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.
* 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:
* If testing the vehicle with the battery cables still connected, wiggle the EL 42000 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.
* If correct connections to the battery terminal bolts in the vehicle are in doubt, perform the following steps:
1. Disconnect the negative battery cable.
2. Disconnect the positive battery cable.
3. Install the test adapters on the terminals.
4. Follow the instructions for testing a removed battery.
* 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.
3. 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.
4. Follow the instructions for testing a removed battery.
5. 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.
* 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 EL 42000 or GM P/N 12303040 terminal adapters. If the adapters that are provided with the EL 42000 require replacement, use GM P/N 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.
Reference Information
Schematic Reference
Starting and Charging Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Starting System Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Control Module References) for scan tool information
Special Tools
EL 42000 - Battery Tester
For equivalent regional tools, refer to Special Tools (Tools and Equipment).
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 C1 battery for a cracked, broken, or damaged case, which may be indicated by battery acid leakage.
• If there is any apparent damage, replace the C1 battery.
2. Verify the cold cranking amperage and amp hour rating of the C1 battery to the original C1 battery or original equipment (OE) specification. Refer to Battery Usage (Battery Usage).
• If the C1 battery does not meet or exceed specifications, replace the C1 battery.
3. Verify that the C1 battery cables are clean and tight. The C1 battery terminal bolts should be torqued as specified in Fastener Tightening Specifications (Specifications).
• If the C1 battery cables need to be cleaned, clean as required and tighten as specified.
• If the C1 battery cables are damaged, replace then tighten as specified.
4. Install the EL 42000 and follow directions supplied by the tester.
• If the tester calls for charging the C1 battery, refer to Battery Charging (Procedures).
5. The battery should not have a history of being discharged or having low voltage.
• If the battery has frequently been discharged or had low voltage while the engine is running, refer to Charging System Test (Charging System Test).
• If the battery has frequently been discharged or had low voltage while the ignition is OFF, refer to Battery Electrical Drain/Parasitic Load Test (Battery Electrical Drain/Parasitic Load Test).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Battery Positive Cable Replacement (Diesel) (Battery Positive Cable Replacement)Battery Positive Cable Replacement (Gas) (Battery Positive Cable Replacement)Battery Positive Cable Replacement (TP2) (Battery Positive Cable Replacement (TP2))
* Battery Negative Cable Replacement (Diesel) (Service and Repair)Battery Negative Cable Replacement (V8) (Service and Repair)Battery Negative Cable Replacement (V6) (Service and Repair)
* Battery Replacement (Battery Replacement)