2010 Cadillac CTS Sedan AWD V6-3.6L Page 1325
* The engine coolant temperature (ECT) sensor is warmer than 60掳C (140掳F).
* The increase in engine speed is less than a range of 500-2300 RPM per second.
* The increase in engine load is less than a range of 50-100 kPa per second.
* DTCs P0327, P0328, P0332, and P0332 run continuously once the above conditions are met for approximately 20 s.
Conditions for Setting the DTC
P0326 and P0331
The ECM detects a short to ground or a voltage on the knock sensor signal circuits in 25 of 250 test samples. The condition exists for greater than 1
s or for a cumulative of 10 s.
P0327 or P0332
The ECM detects the knock sensor signal voltage is less than the calculated minimum for a predetermined engine noise level. The condition exists
during 2 consecutive tests, for greater 1 s or a cumulative of 10 s.
P0328 or P0333
The ECM detects the knock sensor signal voltage is greater than the calculated maximum for a predetermined engine noise level. The condition
exists during 2 consecutive tests, for greater 1 s or a cumulative of 10 s.
Action Taken When the DTC Sets
DTCs P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.
Diagnostic Aids
* Inspect the knock sensor for physical damage. A knock sensor that is dropped or damaged may cause a DTC to set.
* Inspect the knock sensor for proper installation. A knock sensor that is loose or over torqued may cause a DTC to set. The knock sensor
should be free of thread sealant. The knock sensor mounting surface should be free of burrs, casting flash, and foreign material.
* The knock sensor must be clear of hoses, brackets, and engine electrical wiring.
* The normal voltage on the knock sensor signal and low reference circuits is 2.43 V when the knock sensor is disconnected.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine at operating temperature, all accessories OFF. Engine speed greater than 2,000 RPM, observe the appropriate scan tool knock sensor
signal voltage parameter. The voltage should be greater than 4 V.
2. Engine idling, move the related harnesses and connectors for the knock sensor circuits while observing the scan tool knock sensor signal
voltage parameters. The voltage should remain steady with no abrupt changes.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
