P2438
DTC P2432, P2433, P2437, or P2438
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P2432
-
Secondary Air Injection System Pressure Sensor Circuit Low Voltage Bank 1
DTC P2433
-
Secondary Air Injection System Pressure Sensor Circuit High Voltage Bank 1
DTC P2437
-
Secondary Air Injection System Pressure Sensor Circuit Low Voltage Bank 2
DTC P2438
-
Secondary Air Injection System Pressure Sensor Circuit High Voltage Bank 2
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. Secondary air injection pressure sensors, which are integral to the shutoff and check valves, are used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5 V reference circuits and provides a ground for the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within each bank of the secondary air injection system.
Conditions for Running the DTC
* DTC P0606, P0641, or P0651 is not set.
* The ignition is ON, or the engine is running.
* The DTC runs continuously when the above conditions exist.
Conditions for Setting the DTC
P2432 or P2437
The ECM detects that the corresponding bank 1 or bank 2 secondary air injection pressure sensor signal is less than 0.3 V for greater than 6 s.
P2433 or P2438
The ECM detects that the corresponding bank 1 or bank 2 secondary air injection pressure sensor signal is greater than 4.7 V for greater than 6 s.
Action Taken When the DTC Sets
DTCs P2432, P2433, P2437 and P2438 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P2432, P2433, P2437 and P2438 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Secondary Air Injection System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0651 is not set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
2. Verify the scan tool BARO pressure parameter is within the range specified in the Altitude Versus Barometric Pressure Altitude Versus Barometric Pressure table.
3. Verify the scan tool AIR Pressure Sensor in each bank and the BARO pressure parameters are within 3 kPa (0.4 psi).
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 appropriate Q29 secondary air injection solenoid valve.
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 ohms between the low reference circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
• If 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 engine control module.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
4. Verify the corresponding scan tool AIR Press Sen voltage parameter is less than 0.5 V.
• If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the corresponding scan tool AIR Press Sen voltage parameter is greater than 4.8 V.
• If 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 engine control module.
6. If all circuits test normal, test or replace the Q29 secondary air injection solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Secondary Air Injection Bypass Valve Replacement - Left Side Secondary Air Injection Bypass Valve Replacement - Left Side for secondary air injection shutoff and check valve and pressure sensor replacement-Left Side.
* Secondary Air Injection Bypass Valve Replacement - Right Side Secondary Air Injection Bypass Valve Replacement - Right Side for secondary air injection shutoff and check valve and pressure sensor replacement-Right Side.
* Control Module References Control Module References for ECM replacement, setup, and programming