GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Special Tools

J 42000 Digital Battery Tester

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.

Note: 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.

Step

Action

Values

Yes

No

1

Inspect the battery for a cracked, broken, or damaged case, which may be indicated by battery acid leakage.

Is the battery OK?

--

Go to Step 2

Go to Step 19

2

Compare the cold cranking amperage (CCA) and reserve capacity (RC) of the battery to the original battery or original equipment (OE) specification. Refer to Battery Usage.

Does the battery meet or exceed the specification?

--

Go to Step 3

Go to Step 19

3

Does the hydrometer display a yellow dot?

--

Go to Step 4

Go to Step 5

4

Tap the hydrometer lightly on top with the handle of a small screwdriver in order to dislodge any air bubbles inside the battery.

Does the hydrometer display a yellow dot?

--

Go to Step 19

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Attempt to rotate the negative battery cable connector clockwise with light finger pressure.

Does the negative connector rotate?

--

Go to Step 6

Go to Step 7

6

Use a torque wrench in order to verify the torque of the negative battery terminal bolt.

Is the torque at the specified value?

5 N·m (44 lb in)

Go to Step 8

Go to Step 7

7

Warning: Refer to Battery Disconnect Warning in the Preface section.

Disconnect the negative battery cable.

Is the cable disconnected?

--

Go to Step 9

--

8

    Warning: Refer to Battery Disconnect Warning in the Preface section.

  1. Disconnect the negative battery cable.
  2. Inspect for the following conditions and repair as needed:
  3. • The cable bolt is too long or deformed at the end.
    • There is foreign material present inside the nut in the battery terminal.
    • Damage to the battery terminal face or cable connector ring

Is the repair complete?

--

Go to Step 9

--

9

Rotate the positive battery cable connector clockwise with light finger pressure.

Does the positive connector rotate?

--

Go to Step 10

Go to Step 11

10

Use a torque wrench in order to verify the torque of the positive battery terminal bolt.

Is the torque at the specified value?

5 N·m (44 lb in)

Go to Step 12

Go to Step 11

11

Warning: Refer to Battery Disconnect Warning in the Preface section.

Disconnect the positive battery cable.

Is the cable disconnected?

--

Go to Step 13

--

12

    Warning: Refer to Battery Disconnect Warning in the Preface section.

  1. Disconnect the positive battery cable.
  2. Inspect for the following conditions and repair as needed:
  3. • The cable bolt is too long or deformed at the end.
    • There is foreign material present inside the nut in the battery terminal.
    • Damage to the battery terminal face or cable connector ring

Is the repair complete?

--

Go to Step 13

--

13

  1. Clean and wire brush the lead face of both battery terminals and the metal contact rings in both cable connectors.
  2. Remove the bolts from the cable connectors in order to provide access to the connector rings as needed.
  3. If either of the battery terminals or the cable rings are excessively damaged or corroded, replace as needed.

Is the repair complete?

--

Go to Step 14

--

14

  1. Connect the positive battery cable to the battery positive terminal.
  2. Tighten the cable bolt to the specified value.

Is the cable bolt properly tightened?

5 N·m (44 lb in)

Go to Step 15

--

15

  1. Connect the negative battery cable to the battery negative terminal.
  2. Tighten the cable bolt to the specified value.

Is the cable bolt properly tightened?

5 N·m (44 lb in)

Go to Step 16

--

16

Note: Ensure that all of the electrical loads are turned OFF.

  1. Install the J 42000 Digital Battery Tester.
  2. Follow the directions supplied with the tester.
  3. Follow any direction displayed on the tester.

Did the tester pass the battery?

--

Go to Step 17

Go to Step 18

17

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.

  1. Press the CODE button on the J 42000 .
  2. Write the displayed code on the repair order.

Did you complete the repair?

--

Battery OK

--

18

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.

  1. Press the CODE button on the J 42000 .
  2. Write the displayed code on the repair order.
  3. Replace the battery.

Did you complete the replacement?

--

Battery OK

--

19

Replace the battery.

Did you complete the replacement?

--

Battery OK

--