2010 Cadillac CTS Sedan AWD V6-3.6L Page 1015
* If the vehicle has sat overnight, the B66 IAT sensor and the B34 ECT sensor values should display within 3掳C (5掳F).
* High resistance on either the B66 IAT sensor signal circuit or the B66 IAT sensor low reference circuit could set a DTC.
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
Special Tools
J 35616 Connector Test Adapter Kit
Circuit/System Verification
1. Engine idling, DTC P0111, P0112, or P0113 should not set.
2. 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.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.
2. Remove the fuse that supplies B+ to circuit terminal 56-X2 of the ECM.
Caution: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current
draw.
3. Test for less than 5 ohm between the low reference circuit terminal E and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the
circuit/connections test normal, replace the K20 ECM.
4. Install the fuse that supplies B+ to circuit terminal 56-X2 of the K20 ECM.
5. Ignition ON, verify that the scan tool IAT sensor parameter is at -40掳C (-40掳F).
瀚慖f warmer than the specified value, test the signal circuit terminal D for a short to ground. If the circuit/connections test normal, replace
the K20 ECM.
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.
6. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal D and ground circuit terminal C. Verify the IAT sensor
parameter is warmer than 134掳C (274掳F).
瀚慖f colder than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit/connections test
normal, replace the K20 ECM.
7. If all circuits/connections test normal, test or replace the B75B MAF/IAT sensor.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B75B MAF/IAT sensor.
