GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 42000 Battery Tester

Diagnostic Aids

Important: 

   • Failure to properly understand the battery and its function could lead to a misdiagnosis and unneeded repairs. Refer to Battery Description and Operation and Battery Common Causes of Malfunction for more information.
   • If testing an AGM battery with the J 42000 , add 100 to the CCA rating of the battery and enter that amount into the tester when prompted for the CCA rating. For instance, if the AGM batteries CCA rating is 500 amps, enter 600 into the J 42000 . Perform this modification only if the J 42000 does not ask if you are testing an AGM battery. If these instructions are not followed when testing an AGM battery, an invalid test result and invalid test code will be obtained on the J 42000 .
   • 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.
   • When the J 42000 inquires "has the battery been charged", answer yes only if the battery was charged on this visit to the dealership.

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 (top post battery) or terminal bolt (side terminal battery). This may cut through any coating or through any oxidation that may be present on the terminal or bolt.
        Even a new terminal or bolt may contain a protective coating that can insulate or cause a resistance in the test circuit.
    • If correct connections to the battery terminal bolts (side terminal battery) 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 an Out-of-Vehicle test.
    • 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 on side terminal batteries.
        4. Follow the instructions for an Out-of-Vehicle test.
        5. Replace the battery only if the Out-of-Vehicle test shows a REPLACE BATTERY or BAD CELL-REPLACE result. This prevents battery replacements that are due only to faulty battery cable connections.
    • Use the correct terminal adapters on side terminal batteries.
        Do not use any common bolts or a combination of bolts, nuts, and or washers as adapters when testing the battery.
        Use the test adapters that are provided with the J 42000 or P/N 12303040 terminal adapters. If the adapters that are provided with the J 42000 require replacement, use 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.

Step

Action

Values

Yes

No

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.

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. If the battery is replaced due to failing the test, only an Out-of-Vehicle test code is valid for warranty purposes.

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 15

2

Compare the cold cranking amperage (CCA), and reserve capacity (RC) and/or amp hour (AH) rating 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 15

3

  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 4

Go to Step 5

4

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

Is the torque above the specified value?

10 N·m (88 lb in)

Go to Step 9

Go to Step 8

5

Attempt to rotate the positive battery cable connector clockwise with light finger pressure.

Does the positive connector rotate?

--

Go to Step 7

Go to Step 6

6

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

  1. Install the J 42000 Battery Tester.
  2. Follow the directions supplied with the tester for an In-Vehicle test.
  3. Follow any directions displayed on the tester.
  4. If the tester calls for charging the battery, refer to Battery Charging .

Did the tester pass the battery?

--

Go to Step 14

Go to Step 8

7

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

Is the torque above the specified value?

10 N·m (88 lb in)

Go to Step 10

Go to Step 8

8

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

Did you complete the repair?

--

Go to Step 11

--

9

  1. Disconnect the negative battery cable.
  2. Inspect for the following conditions and repair as needed:
  3. Side Post Battery

    • 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

    Top Post Battery

    • There is foreign material present on the battery terminal face or cable connector ring.
    • Damage to the battery terminal face or cable connector ring

Did you complete the repair?

--

Go to Step 10

--

10

  1. Disconnect the positive battery cable.
  2. Inspect for the following conditions and repair as needed:
  3. Side Post Battery

    • 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

    Top Post Battery

    • There is foreign material present on the battery terminal face or cable connector ring.
    • Damage to the battery terminal face or cable connector ring

Did you complete the repair?

--

Go to Step 11

--

11

Important: Ensure that both battery cables are disconnected and the directions for an Out-of-Vehicle test are followed.

  1. Install the J 42000 .
  2. Follow the directions supplied with the tester for an Out-of-Vehicle test.
  3. Follow any directions displayed on the tester.
  4. If the tester calls for charging the battery, refer to Battery Charging .

Did the tester pass the battery?

--

Go to Step 12

Go to Step 15

12

  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?

--

Go to Step 13

--

13

  1. Connect the positive battery cable to the batteries positive terminal.
  2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Tighten the positive battery cable to the specified value.
  4. Connect the negative battery cable to the battery negative terminal.
  5. Tighten the negative battery cable to the specified value.

Are the cable bolts properly tightened?

17 N·m (13 lb ft)

Battery OK

--

14

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

Did you complete the replacement?

--

Battery OK

--

15

Replace the battery. Refer to Battery Replacement .

Did you complete the replacement?

--

Battery OK

--