Test Description
WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: Tests for specified voltage on the brake pressure signal circuit.
- 3: Checks to see if the brake pressure signal circuit voltage was below specified voltage.
- 4: Checks to see if the brake pressure signal circuit voltage was above specified voltage.
- 5: Tests for a short to ground in the 5 volt reference circuit of the brake pressure sensor.
- 6: Tests for a short to voltage in the 5 volt reference circuit of the brake pressure sensor.
- 7: Tests for a high resistance or an open in the ground circuit of the brake pressure sensor.
- 8: Checks the brake pressure sensor connector for poor connections.
- 9: Checks the EBCM connector for poor connections.
DTC C0870
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: ABS Schematics Connector End View Reference: ABS Connector End Views |
||||
| 1 | Did you perform the ABS Diagnostic System Check? | - | Go to Step 2 | Go to Diagnostic System Check - ABS |
| 2 |
|
4.4-5.6 V | Go to Diagnostic Aids | Go to Step 3 |
| 3 |
|
4.4 V | Go to Step 4 | Go to Step 5 |
| 4 | Using the DMM, measure the voltage between pin 17 and pin 15 of the J 39700
. See Special Tools and Equipment . Is the voltage less than the specified value? |
5.6 V | Go to Step 8 | Go to Step 6 |
| 5 | Test the 5 volt reference circuit of the brake pressure sensor for a short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 9 |
| 6 | Test the 5 volt reference circuit of the brake pressure sensor for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 7 |
| 7 | Test the ground circuit of the brake pressure sensor for a high resistance or an open. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 9 |
| 8 | Inspect for poor connections at the harness connector of the brake pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 10 |
| 9 | Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 11 |
| 10 | Replace the brake pressure sensor. Refer to Brake Fluid Pressure Sensor Replacement . Did you complete the replacement? |
- | Go to Step 12 | - |
| 11 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? |
- | Go to Step 12 | - |
| 12 |
|
- | Go to Step 2 | System OK |