Circuit Description
The instrument cluster receives voltage inputs from three ignition signals. The instrument cluster receives voltage from the IGN0 fuse when the ignition switch is in the accessory, on or start positions. The instrument cluster receives voltage from the CLUSTER fuse when the ignition switch is in the on and start positions. The instrument cluster receives voltage form the CRANK SIGNAL fuse when the ignition switch is in the START position. If the instrument cluster does not receive any of the following voltage input combinations, a malfunction is present and this DTC sets:
| • | If circuit 39 is active and circuit 1500 is inactive. |
| • | If circuit 806 is active and circuit 1500 is inactive. |
| • | If circuit 806 is active and circuit 39 is inactive. |
Conditions for Setting the DTC
| • | The instrument cluster does not detect voltage from circuit 1500 when the ignition switch is in the accessory, on or start positions, but the instrument cluster detects voltage in circuit 39 when the ignition switch is in the on or start positions. |
| • | The instrument cluster detects voltage in circuit 806 when the ignition switch is in the start position, but the instrument cluster does not detect voltage in circuit 1500 when the ignition switch is in the accessory, on or start positions. |
| • | The instrument cluster detects voltage in circuit 806 when the ignition switch is in the start position, but the instrument cluster does not detect voltage in circuit 39 when the ignition switch is in the on or start positions. |
| • | All conditions must be present for more than 0.3 seconds. |
Action Taken When the DTC Sets
| • | The instrument cluster stores DTC B0608 in memory. |
| • | The SERVICE VEHICLE SOON indicator turns on. |
Conditions for Clearing the DTC
| • | Under all fault conditions the ignition switch must be cycled from on to off, back to on before this DTC can change from current to history. |
| • | The instrument cluster no longer detects an open or short to B+ in circuits 39, 806 and 1500. |
| • | A history DTC will clear after 100 drive cycles if the condition for this DTC is no longer present. |
| • | Use a scan tool. |
Diagnostic Aids
The following conditions may cause an intermittent malfunction to occur:
| • | An intermittent open or short to voltage in circuit 39, 806 or 1500. |
| • | Poor connections at the instrument cluster or fuse block. |
| • | The instrument cluster is always detecting B+ from one or more of these 3 inputs. |
| • | The instrument cluster is never recognizing B+ from circuit 39, 806 or 1500. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Always perform the instrument cluster diagnostic system check before attempting to diagnose DTC B0608.
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This test will determine if there is a short to B+ in circuit 39.
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This test checks for an open in circuit 39.
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This test will determine if there is a short to B+ in circuit 806.
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This test checks for an open in circuit 806.
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This test will determine if there is a short to B+ in circuit 1500.
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This test checks for an open in circuit 1500.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the instrument cluster diagnostic system check performed? | -- | Go to Step 2 | ||
Does the test light stay off? | -- | Go to Step 4 | Go to Step 3 | |
3 | Repair a short to B+ in circuit 39. Is the repair complete? | -- | Go to Step 15 | -- |
Is the test light on? | -- | Go to Step 5 | Go to Step 6 | |
Does the test light stay off? | -- | Go to Step 8 | Go to Step 7 | |
6 | Repair poor connection or open in circuit 39 between the instrument cluster harness connector terminal A5 and the fuse block terminal A6. Is the repair complete? | -- | Go to Step 15 | -- |
7 | Repair short to B+ in circuit 806. Is the repair complete? | -- | Go to Step 15 | -- |
Upon turning the ignition switch to the start position, did the test light turn on? | -- | Go to Step 9 | Go to Step 10 | |
Does the test light stay off? | -- | Go to Step 11 | Go to Step 12 | |
10 | Repair poor connection or open in circuit 806 between the instrument cluster harness connector terminal A6 and the fuse block terminal A4. Is the repair complete? | -- | Go to Step 15 | -- |
Did the test light turn on when the ignition switch was in the accessory, on and start positions? | -- | Go to Step 13 | Go to Step 14 | |
12 | Repair short to B+ in circuit 1500. Is the repair complete? | -- | Go to Step 15 | -- |
13 | Replace the instrument cluster. Refer to Instrument Cluster Replacement for service procedure. Is the repair complete? | -- | Go to Step 15 | -- |
14 | Repair poor connection or open in circuit 1500. Is the repair complete? | -- | Go to Step 15 | -- |
15 |
Are there any DTCs stored in the instrument cluster? | -- | System OK |
