2010 Cadillac Truck SRX FWD V6-3.0L Page 1135
* Depending on the ambient temperature, an IAT sensor signal circuit or low reference circuit that is shorted to the MAF sensor signal circuit
can cause a DTC P0113 and/or P0114 to set. This condition causes a rapid fluctuation in the IAT Sensor parameter.
* An IAT sensor signal circuit that is shorted to the MAF sensor ignition circuit can cause a DTC P0113 and/or P0114 to set.
* A MAF sensor ground circuit that is open will cause a DTC P0113 and/or a DTC P0114 to set.
Reference Information
Schematic Reference
Engine Controls Schematics (LAU) (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/Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/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 running, observe the scan tool IAT Sensor parameter. The reading should be between -40 to +149掳C (-40 to +300掳F) depending on
the current ambient temperature and the vehicle operating conditions.
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 terminal 52 X1 of the ECM.
3. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm
between the low reference circuit terminal D 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 tests
normal, replace the K20 ECM.
4. Install fuse that supplies B+ to terminal 52 X1 of the ECM.
5. Ignition ON, verify the scan tool IAT Sensor parameter is colder than -39掳C (-38掳F).
瀚慖f greater than the specified range, test the signal circuit terminal E for a short to voltage. If the circuit tests normal, replace the K20
ECM.
Note: If the fuse in the jumper wire opens, the signal circuit is shorted to voltage and the sensor may be damaged.
6. Install a 3 A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool IAT parameter is greater than 149掳C
(300掳F).
瀚慖f less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the K20 ECM.
7. If all circuits test normal, test or replace the B75B MAF/IAT sensor.
Component Testing
Measure and record the resistance of the B66 IAT sensor at various ambient temperatures, then compare those measurements to the Temperature
Versus Resistance - Intake Air Temperature Sensor (See: Powertrain Management/Computers and Control Systems/Specifications/Temperature
