Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSPONTIAC2008GRAND PRIX BASEREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 121 (VARIABLE EFFORT STEERING SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDTC C0450TEST DESCRIPTION
2008 Pontiac Grand Prix Base
Test Description
2008 Pontiac Grand Prix BaseSECTION Test Description
WARNING: This page is about a different car, the 2007 Buick LaCrosse and 2007 Buick Allure. 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: This step tests if the Commanded and Feedback Current parameters are within specification in their active state.
- 3: Perform the VES test located under Special Functions. This test may indicate if the VES actuator is mechanically bound.
- 4: This step tests if the resistance of the VES actuator is within specification.
- 7: This step tests the control circuit of the VES actuator for a short to ground.
- 13: Perform the setup procedure after EBCM replacement.
DTC C0450
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Steering Assist Schematics Connector End View Reference: Steering Assist Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 |
|
0.90-1.00 A | Go to Step 3 | Go to Step 4 |
| 3 | Using the scan tool, select F1 VES Test. Does the scan tool indicate Test Passed? |
- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 4 |
| 4 |
|
2.5-10 Ω | Go to Step 5 | Go to Step 12 |
| 5 | Test the VES actuator and actuator harness for a short to ground. Refer to Testing for Short to Ground
and Wiring Repairs
in Wiring Systems. Was a short to ground located? |
- | Go to Step 6 | Go to Step 7 |
| 6 | Visually inspect the actuator harness for any cut, chaffed or damaged wires. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 14 |
| 7 | Test the control circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 8 |
| 8 | Test the control circuit of the VES actuator for an open or short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 9 |
| 9 | Test the return circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 10 |
| 10 | Test the return circuit of the VES actuator for an open or a short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 11 |
| 11 | Inspect for poor connections at the harness connector of the electronic brake control module (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 15 | Go to Step 13 |
| 12 | Inspect for poor connections at the harness connector of the VES actuator. Refer to Testing for Intermittent Conditions and Poor Connections
andConnector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 15 | Go to Step 14 |
| 13 |
IMPORTANT:
Always perform the setup procedure for the EBCM.
|
- | Go to Step 15 | - |
| 14 | Replace the VES actuator. Refer to Power Steering Gear Replacement
in Power Steering System. Did you complete the replacement? |
- | Go to Step 15 | - |
| 15 |
|
- | Go to Step 2 | System OK |
RENDER: 1.0x
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.