2010 Cadillac Truck SRX FWD V6-3.0L Page 2049
瀚慖f any of the above DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code
Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.
2. Observe the scan tool Secondary Air Injection Pressure Sensor voltage parameter. The reading should be between 1.0-4.0 V.
3. Compare the scan tool BARO pressure parameter to the Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and
Control Systems/Specifications/Altitude Versus Barometric Pressure) table. The BARO should be within the specified range displayed in the
table for the specific altitude.
瀚慖f not within the specified range, refer to DTC P2227, P2228, or P2229 (LAU) (See: P Code Charts/P2227) for further diagnosis.
4. 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 B157 secondary air injection pressure sensor.
2. 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 2 and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20
ECM.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the K20 ECM.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Verify the scan tool Secondary Air Injection Pressure Sensor voltage parameter is less than 0.5 V.
瀚慖f greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1. Verify the scan tool Secondary
Air Injection Pressure Sensor voltage parameter is greater than 4.8 V.
瀚慖f less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the
K20 ECM.
6. If all circuits test normal, test or replace the B157 secondary air injection pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Secondary Injection Shutoff Valve Pressure Sensor Replacement (See: Powertrain Management/Emission Control Systems/Air Injection/Air
Injection Check Valve/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P2433
DTC P2431-P2433
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P2431
- Secondary Air Injection System Pressure Sensor Performance
DTC P2432
- Secondary Air Injection System Pressure Sensor Circuit Low Voltage
