Diagnostic Aids
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: 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. 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 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, nut, and washers as adapters when testing the battery. |
| Use the test adapters that are provided with the J 42000 or GM P/N 12303040 terminal adapters. If the adapters that are provided with the J 42000 require replacement, only use adapters with the GM P/N 12303040. Any other adapters may not contact the correct areas of the battery terminal, causing 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 of the battery to the original battery or Original Equipment 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 in order 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 |
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(88 lb in) | 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.
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(88 lb in) | 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.
Is the repair complete? | -- | Go to Step 13 | -- | ||||||
13 |
Are the metal connecting parts clean and in good condition? | -- | Go to Step 14 | -- | ||||||
14 |
Is the cable bolt correctly tightened? | 15 N·m (11 lb ft) | Go to Step 15 | -- | ||||||
15 |
Is the cable bolt correctly tightened? | 15 N·m (11 lb ft) | Go to Step 16 | -- | ||||||
16 |
Important: Ensure all electrical loads are turned OFF.
Did the tester pass the battery? | -- | Go to Step 17 | Go to Step 18 | ||||||
17 |
Did you complete this action? | -- | Battery OK | -- | ||||||
18 |
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 | -- |
