GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

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

Important: The 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.

Adhere to the following instructions in order to avoid an incorrect diagnosis due to poor connections:

    • When testing the vehicle with the battery cables still connected, rock the J 42000 clips back and forth on the terminal bolt in order to cut through any coating or 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 it is uncertain that correct connections can be made to the battery terminal bolts in the vehicle, 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 the battery outside of the vehicle.
    • If a REPLACE BATTERY result is obtained for a battery that is below 4°C (40°F), perform the following steps:
        1. Disconnect the negative battery cable.
        2. Disconnect the positive battery cable.
        3. Allow the battery to sit in a warm place (above 15°C (60°F) for 6 hours.
        4. Install the approved adapters.
        5. Follow the instructions for testing the battery outside of the vehicle.
        6. Replace the battery only if the second test shows a REPLACE BATTERY result.

For warranty purposes, use the test code from the second test.

    • If a REPLACE BATTERY result is obtained 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 approved adapters.
        4. Follow the instructions for testing the battery outside of the vehicle.
        5. Replace the battery only if the second test shows a REPLACE BATTERY result.

For warranty purposes, use the test code from the second test.

    • Use the approved terminal adapters.
        Do not use any common bolts or a combination of bolts, nuts, and washers as adapters when testing the battery.
        Use the test adapters that are provided with the J 42000 tester or GM part number 12303040 terminal adapters. If the adapters that are provided with the J 42000 tester require replacement, only use adapters with the GM part number 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.

Important: For warranty purposes, always place the test code displayed by the tester on the repair order. The number is a unique identifier that describes the test data for a particular battery at a particular time.

While the test code may occasionally repeat when retesting the same battery, it is more likely that a different code will result each time the battery is tested.

Step

Action

Value(s)

Yes

No

1

Inspect the battery for a cracked, broken, or damaged case, which may 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 specifications?

--

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 to dislodge any air bubbles inside the battery.

Does the hydrometer still 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 to loosen the negative battery terminal bolt.

Is the torque above the specified value?

10 N·m

Go to Step  8

Go to Step  7

7

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

Disconnect the negative battery cable.

Is the cable disconnected?

--

Go to Step  9

--

8

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

Ensure the negative battery cable is disconnected.

Inspect for the following conditions and repair as needed:

    • 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 to loosen the positive battery terminal bolt.

Is the torque above the specified value?

10 N·m

Go to Step  12

Go to Step  11

11

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

Disconnect the positive battery cable.

Is the cable disconnected?

--

Go to Step  13

--

12

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

  1. Ensure the positive battery cable is disconnected.
  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 the battery terminals or the cable rings are excessively damaged or corroded, replace as needed.

Are the metal connecting parts clean and in good condition?

--

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. Refer to Fastener Tightening Specifications in this section.

Is the cable bolt properly tightened?

--

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. Refer to Fastener Tightening Specifications in this section.

Is the cable bolt properly tightened?

--

Go to Step  16

--

16

Important: Make sure all electrical loads are turned OFF.

  1. Install the J 42000 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

  1. Press the CODE button on the J 42000.
  2. For warranty purposes, write the displayed code on the repair order.

Did you complete this action?

--

Battery OK

--

18

  1. Press the CODE button on the J 42000.
  2. For warranty purposes, write the displayed code on the repair order.

Replace the battery. Refer to Battery Replacement .

Did you complete the replacement?

--

Battery OK

--

19

Replace the battery. Refer to Battery Replacement .

Did you complete the replacement?

--

Battery OK

--