Circuit/System Testing

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT:

Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
If an engine mechanical noise can be heard, repair the condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical .

Test for an intermittent and for a poor connection at the affected KS.
With the ignition OFF, disconnect the affected KS.
With the ignition OFF, measure the resistance for infinite ohms from the sensor signal terminal on the KS to a good ground and the low reference terminal on the KS to a good ground with a DMM.
- If resistance does not measure infinite ohms at both terminals, then replace the affected KS.

IMPORTANT: Do not tap on plastic engine components.

Connect the DMM between the terminals of the affected KS. Set the DMM to the 400 Hz scale, let stabilize at 0 Hz. Tap on engine block with a non-metallic object near the affected KS while observing the signal indicated on the DMM.
- If the DMM does not display a fluctuating frequency while tapping on the engine block then replace the affected KS.
Turn the ignition ON, engine OFF. Set the DMM to the DC voltage scale. Measure for 4.2 volts from the KS signal circuit to a good ground and the KS low reference circuit to a good ground with the DMM.
- If over 4.2 volts with the ignition OFF, disconnect the control module and test the KS signal circuit or the KS low reference circuit for a short to voltage.
- If under 4.2 volts with the ignition OFF, disconnect the control module test the KS signal circuit or the KS low reference circuit for an open, short to ground or high resistance.
Test for intermittent or poor connections at the control module.
If all circuits test normal, then replace the control module.