Battery Inspection/Test

Battery Inspection/Test

Diagnostic Aids

Tools Required

J 42000 Digital Battery Tester

Caution:
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.

Important:
The battery test using the 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.


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 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 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 test adapters.

4. Follow the instructions for testing a removed battery.

5. Replace the battery only if the second test shows a REPLACE BATTERY result.

6. 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, nuts, and washers as adapters when testing the battery.