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.
Circuit/System Testing
2008 Pontiac Grand Prix BaseSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the TDM.
- Verify that there is less than 1.0 ohm between the ground circuit terminal 3 and the negative terminal of the battery.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON. measure the voltage between the B+ circuit terminal 1 and the ground circuit terminal 3. Verify that the difference between the voltage at the TDM connector and the voltage at the battery terminals is less than 1 volt.
- If greater than the specified value, test the B+ circuit for a short to ground or an open/high resistance.
- If all circuits test normal, replace the TDM.
RENDER: 1.0x
NO RELATED
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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.