Diagnostic Aids
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Refer to Battery Disconnect Caution
.
IMPORTANT:
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:
- Disconnect the negative battery cable.
- Disconnect the positive battery cable.
- 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.
IMPORTANT: 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.