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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the IC module connector. Test for less than 3 ohms between the IC module ground circuit IC module terminal K and battery ground
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  2. Ignition ON, test for B+ between the IC module ignition voltage circuit IC module terminal P and ground.
    • If less than the specified range, test the IC module ignition voltage circuit for an open/high resistance or short to ground.
  3. Connect the IC module.
  4. Disconnect the CKP sensor connector.
  5. Test for less than 1 ohm on the low reference circuit CKP sensor terminal C.
    • If greater than the specified value, test the low reference circuit for an open/high resistance.
  6. Ignition ON, test for more than 10 volts between the 12-volt reference circuit CKP sensor terminal D and ground.
    • If less than the specified range, test the 12-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the IC module.
  7. Ignition ON, test for 4-8 volts between the signal circuit CKP sensor terminal A and ground.
    • If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the IC Module.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the IC Module.
  8. Ignition ON, using a jumper wire connected to ground, momentarily touch the CKP sensor 2 signal circuit CKP sensor terminal A repeatedly. The CKP Sensor parameter should increment.
    • If the CKP Sensor B parameter increments, replace the CKP sensor.
  9. Ignition OFF, disconnect the IC module connector. Ignition ON, using a jumper wire connected to B+, momentarily touch the low resolution engine speed signal circuit IC module terminal D repeatedly. The CKP Sensor parameter should increment.
    • If the CKP Sensor B parameter increments, replace the IC module.
    • If the CKP Sensor B parameter does not increment, test the low resolution engine speed signal for an open/high resistance, short to ground, or a short to voltage. If all circuits test OK, replace the PCM.
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