Diagnostic Aids
By manipulating the harnesses at the various connectors it is often possible to isolate the cause of the circuit interruption. This harness can then be removed and repaired. Inspect for any damage to the harness which could cause an intermittent open or short to ground or backed out terminals at the instrument cluster connectors, broken connector locks, improperly formed or damaged terminals. The multimeter allows continuity of the wiring harness circuit 774 to be checked. If the fault cannot be found in the harness then the fault may lie in the SDM or the BCM. Refer to Diagnostic Starting Point - Computer/Integrating Systems for further diagnosis.
DTC 12 - No Serial Data From SDM
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
|
- | Go to Step 3 | Go to Scan Tool Does Not Communicate with UART Device |
| 3 |
|
- | Go to Step 4 | Go to Step 6 |
| 4 |
|
- | Go to Step 5 | Go to Step 7 |
| 5 |
|
- | Go to Step 8 | Go to Step 7 |
| 6 | Repair the open or high resistance in the Secondary UART Serial Data circuit between the BCM and the SDM. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 8 | - |
| 7 | Repair the open or high resistance in the Secondary UART Serial Data circuit between the powertrain control module (PCM) and the powertrain interface module (PIM). Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 8 | - |
| 8 |
|
- | Go to Step 2 | System OK |