Circuit Description
DTC C1277 identifies a solenoid that cannot be energized due to a short to voltage in the solenoid driver circuitry. The malfunction can affect ABS operation since the flow of brake fluid to the wheel cylinder cannot be stopped. The unstoppable flow of brake fluid to the wheel cylinder makes ABS operation for that channel impossible.
Conditions for Setting the DTC
DTC C1277 can set only when the brake solenoid valve is commanded on. A malfunction exists if the EBCM/EBTCM detects the left front brake solenoid valve control circuit voltage is not within specifications.
Action Taken When the DTC Sets
| • | A malfunction DTC stores. |
| • | The ABS/TCS disables. |
| • | The amber ABS/TCS warning indicators turn on. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTC function is used. |
| • | 100 drive cycles pass with no DTC detected. |
Diagnostic Aids
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. Refer to the Scan Tool manual or Scan Tool Diagnostics located in this section for the procedure.
Thoroughly inspect any circuitry that may cause the intermittent complaint for the following conditions:
| • | Rubbed-through wire insulation |
| • | A broken wire inside the insulation |
| • | Backed out terminals |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | Poor terminal-to-wiring connections |
| • | Physical damage to the wiring harness |
Important: Zero the J 39200 test leads before making any resistance measurements.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | |
2 |
Is any voltage present during this test? | -- | Go to Step 8 | Go to Step 3 |
3 |
Is the resistance within the specified range? | 2.0-5.0ohms | Go to Step 4 | Go to Step 7 |
4 |
Is any voltage present during this test? | -- | Go to Step 8 | Go to Step 5 |
5 |
Is there damage that may cause a short to voltage? | -- | Go to Step 9 | Go to Step 6 |
6 |
Does DTC C1277 set as a current DTC? | -- | Go to Step 10 | Go to Step 11 |
7 | Replace the left front brake solenoid valve. Is the repair complete? | -- | -- | |
8 | Repair the short to voltage in CKT 826. Is the repair complete? | -- | -- | |
9 | Repair the damage that caused a short to voltage. Is the repair complete? | -- | -- | |
10 | Replace the EBCM/EBTCM. Is the repair complete? | -- | -- | |
11 | The malfunction is intermittent or not present at this time. Is a concern still present? | -- | Go to Diagnostic Aids |
