For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Body Control Module (BCM) System Check performed? | -- | Go to Step 2 | Go to Body Control Module System Check
2 |

1. Start the engine.
2. Use the Scan Tool in order to read the BCM to cluster data.

Is the Tach Signal reading active?

--

Go to Step 5

Go to Step 3

3 | Use the J 39200 Digital Multimeter (DMM) in order to measure the AC voltage at the TACH TEST POINT located on the underhood junction block. Does an AC voltage exist? | -- | Go to Step 4 | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls--2.4L or Powertrain On Board Diagnostic (OBD) System Check in Engine Controls--3.1L
4 |

1. Disconnect the instrument cluster.
2. Use the J 39200 DMM in order to measure the AC voltage in CKT 121 at connector terminal A7 of the instrument cluster.

Does an AC voltage exist?

--

Go to Step 5

Go to Step 6

5 | Replace the instrument cluster. Refer to Instrument Cluster Replacement . Is the repair complete? | -- | Go to Body Control Module System Check | --
6 |

1. Disconnect connector C3 of the underhood junction block.
2. Use the J 39200 DMM in order to measure the DC voltage in CKT 121 between terminal F8 of underhood junction block connector C3 and ground.

Does the voltage equal the specified value?

0 V

Go to Step 8

Go to Step 7

7 | Repair the short to positive battery voltage in CKT 121 between terminal F8 of underhood junction block connector C3 and terminal A7 of the instrument cluster connector. Is the repair complete? | -- | Go to Body Control Module System Check | --
8 | Use the J 39200 DMM in order to measure the resistance in CKT 121 between terminal F8 of underhood junction block connector C3 and ground. Does the resistance measure within the specified range? | ∞ | Go to Step 10 | Go to Step 9
9 | Repair the short to ground in CKT 121 between terminal F8 of underhood junction block connector C3 and terminal A7 of the instrument cluster connector. Is the repair complete? | -- | Go to Body Control Module System Check | --
10 | Use the J 39200 DMM in order to measure the resistance in CKT 121 between terminal F8 of underhood junction block connector C3 and terminal A7 of the instrument cluster connector. Does the resistance measure within the specified range? | 0-2 ohms | Go to Step 12 | Go to Step 11
11 | Repair the open in CKT 121 between terminal F8 of underhood junction block connector C3 and terminal A7 of the instrument cluster connector. Is the repair complete? | -- | Go to Body Control Module System Check | --
12 | Replace the underhood junction block. Refer to Underhood Fuse Block Replacement in Engine Electrical. Is the repair complete? | -- | Go to Body Control Module System Check | --