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.
Driver Power Window Inoperative
- Ignition OFF, disconnect the X1 harness connector at the DDS.
- Test for less than 1 ohm between the ground circuit terminal 6 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Ignition OFF, reconnect the harness connector at the DDS.
- Ignition ON, observe the scan tool Driver Window Switch parameters while using the driver power window switch. The reading should change between OFF/UP/DOWN/EXPRESS DOWN.
- If the parameter does not change, replace the DDS.
- Ignition OFF, disconnect the harness connector at the driver window motor.
- Connect a test lamp between control circuit terminal A and control circuit terminal B.
- Ignition ON, command the driver window UP and DOWN by using the driver window switch. The test lamp should turn ON when commanding the UP and DOWN states.
- If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the DDS.
- If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the DDS.
- If all circuits test normal, test or replace the driver window motor.
Passenger Power Window Inoperative
- Ignition OFF, disconnect the X1 harness connector at the PDS.
- Test for less than 1 ohm between the ground circuit terminal 6 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Ignition OFF, reconnect the harness connector at the PDS.
- Ignition ON, observe the scan tool Passenger Window Switch parameters while using the passenger power window switch. The reading should change between OFF/UP/DOWN/EXPRESS DOWN.
- If the parameter does not change, replace the PDS.
- Ignition OFF, disconnect the harness connector at the passenger window motor.
- Connect a test lamp between control circuit termina A and control circuit terminal B.
- Ignition ON, command the passenger window UP and DOWN by using the passenger window switch. The test lamp should turn ON when commanding the UP and DOWN states.
- If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the PDS.
- If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the DDS.
- If all circuits test normal, test or replace the passenger window motor.
Rear Power Window Inoperative
- Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
- Test for less than 1 ohm between ground and the ground circuit listed below:
- Right rear window switch ground circuit terminal E
- Left rear window switch ground circuit terminal F
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal H and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Enable the rear windows by using the window lockout switch.
- Test for more than 10 volts on the control circuit terminal D.
- If less than the specified range, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
- Test for more than 10 volts on the signal circuit terminal C while commanding the rear window DOWN with a scan tool.
- If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
- Test for more than 10 volts on the signal circuit terminal A while commanding the rear window UP with a scan tool.
- If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
- Ignition OFF, reconnect the rear window switch and disconnect the harness connector at the rear window motor
- Connect a test lamp between control circuit terminal A and control circuit terminal B.
- Ignition ON, command the rear window UP and DOWN by using the rear window switch. The test lamp should turn ON when commanding the UP and DOWN states.
- If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the rear window switch.
- If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the rear window switch.
- If all circuits test normal, test or replace the rear window motor.
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.