Diagnostic Aids
Thoroughly inspect the wiring and connectors when diagnosing intermittent DTCs. This will include the following:
- Removal of the protective conduit and inspection of wiring for damage, shorts, and contamination
- Inspection for improperly formed and/or damaged terminals
- Checking terminal contact retention force by using a spare male/female terminal
- Removal of the terminals from the connectors to check for proper terminal to wire crimp
If the driver comments reflect that the ABS warning lamp is ON only during moist environmental changes, such as, rain, snow, vehicle wash, the all wheel speed sensor circuitry should be thoroughly inspected for signs of water intrusion. If the DTC is not current, simulate the effects of water intrusion. Use the following procedure. Spray the suspected area with a 5 percent salt-water solution. Then test-drive the vehicle over various road surfaces, such as, bumps, turns, etc., above 24 km/h (15 mph). If the DTC sets then replace the suspected harness and/or sensor.
When measuring the wheel speed sensor resistance, ensure the vehicle is at room temperature, since resistance will increase with temperature.
Failure to perform the previous steps carefully and fully can result in misdiagnosis, unnecessary component replacement, and reoccurrence of DTC C1206.
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - ABS? | - | Go to Step 2 | Go to Diagnostic System Check - ABS |
| 2 |
|
- | Go to Step 3 | Go to Step 4 |
| 3 | Repair the damage to the left rear wheel speed sensor, jumper harness, and/or the toothed ring. Did you find and correct the condition? |
- | System OK | - |
| 4 | Test-drive the vehicle at various speeds and over various road surfaces. Did DTC C1206 reset? |
- | Go to Step 6 | Go to Step 5 |
| 5 | DTC C1206 is intermittent. Refer to Diagnostic System Check - ABS . Did you find and correct the condition? |
- | System OK | - |
| 6 |
|
800-1600 Ω | Go to Step 8 | Go to Step 7 |
| 7 | Replace the left rear wheel speed sensor. Refer to Wheel Speed Sensor Replacement - Rear . Did you complete the replacement? |
- | System OK | - |
| 8 |
|
OL (open circuit) | Go to Step 9 | Go to Step 7 |
| 9 |
|
2 Ω | Go to Step 11 | Go to Step 10 |
| 10 | Repair the open or high resistance between terminals 5 and 1. Did you find and correct the condition? |
- | System OK | - |
| 11 |
|
2 Ω | Go to Step 3 | Go to Step 12 |
| 12 | Repair the open or high resistance between terminals 6 and 2. Did you find and correct the condition? |
- | System OK | - |
| 13 |
|
1 V | Go to Step 15 | Go to Step 14 |
| 14 | Repair the short to voltage between terminals 5 and 1. Did you find and correct the condition? |
- | System OK | - |
| 15 |
|
1 V | Go to Step 17 | Go to Step 16 |
| 16 | Repair the short to voltage between terminals 6 and 2. Did you find and correct the condition? |
- | System OK | - |
| 17 |
|
OL (open circuit) | Go to Step 19 | Go to Step 18 |
| 18 | Repair the short to ground between terminals 5 and 1. Did you find and correct the condition? |
- | System OK | - |
| 19 |
|
OL (open circuit) | Go to Step 21 | Go to Step 20 |
| 20 | Repair the short to ground between terminals 6 and 2. Did you find and correct the condition? |
- | System OK | - |
| 21 |
|
OL (open circuit) | Go to Step 23 | Go to Step 22 |
| 22 | Repair the short between the 2 circuits. Did you find and correct the condition? |
- | System OK | - |
| 23 |
|
- | Go to Step 24 | System OK |
| 24 | Replace the EBCM. Refer to Brake Modulator Assembly Replacement . Did you complete the replacement? |
- | System OK | - |