Circuit/System Verification

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Ignition - On / Vehicle - In Service Mode
Verify there are no related DTCs set in the following system:
- B52 Heated Oxygen Sensor
- B65 Manifold Absolute Pressure and Intake Air Temperature Sensor
- B75 Mass Airflow Sensor
- B111 Turbocharger/Supercharger Boost Pressure Sensor
- M128 Turbocharger Wastegate Actuator
- Q12 Evaporative Emission Purge Solenoid Valve
- Q17 Fuel Injector
- Q38 Throttle Body
- Q40 Turbocharger Bypass Solenoid Valve
- Barometric Pressure Sensor
- Engine - Mechanical Condition
- Engine Misfire
- Fuel System
- Positive Crankcase Ventilation System
- If a related DTC is set
  Refer to: Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If a related DTC is not set
Verify the scan tool parameter: High Water Content in Oil Detected = No
- If not the specified state
  Refer to: Diagnostic Aids & Advise the customer an oil change may be required.
- Go to next step: If the specified state
Verify the scan tool parameter:
- Engine Underboost Due to Ice in Charge Air Cooler = No
- Ice Detected in Charge Air Cooler = No
- If not the specified state
1. Ignition/Vehicle - Off
2. Verify the condition does not exist with the component and repair as necessary:
  1. {External} Charge Air Cooler - Ice/Restricted/Snow
  2. {Internal} Charge Air Cooler - Ice/Moisture/Restricted
  3. Induction System - Ice/Moisture
- Go to next step: If the specified state
Verify the scan tool parameter: Throttle Body Idle Air Flow Compensation = Less than 90%
- If 90% or greater
  Refer to: Throttle Body Cleaning
- Go to next step: If less than 90%
Verify the scan tool parameter:
- Boost Pressure Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure
- Manifold Absolute Pressure Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure
- If not in the specified range
- {B65 Manifold Absolute Pressure and Intake Air Temperature Sensor} Refer to: DTC P0107 or P0108
- {B111 Turbocharger/Supercharger Boost Pressure Sensor} Refer to: DTC P0237 or P0238
- Go to next step: If in the specified range
Engine - Idling - At normal operating temperature.
Accessories - Off
Verify the scan tool parameter:
- Manifold Absolute Pressure Sensor = 26 to 52 kPa (3.8 to 7.5 PSI) @ Idle Speed
- Manifold Absolute Pressure Sensor = The value should change with accelerator pedal input.
- If not between 26 and 52 kPa (3.8 and 7.5 PSI) or does not change
  Refer to: DTC P0107 or P0108
- Go to next step: If between 26 and 52 kPa (3.8 and 7.5 PSI) and changes
Verify the scan tool parameter: Boost Pressure Sensor = The value should change with accelerator pedal input.
- If the value does not change
  Refer to: DTC P0237 or P0238
- Go to next step: If the value changes
Increase the engine speed slowly to 3k RPM and then back to idle.
Perform the scan tool function: Review Stored Data
Observe the scan tool parameter frame by frame with a scan tool: Mass Airflow Sensor
Verify the scan tool parameter: Mass Airflow Sensor = The value should not spike or drop out.
- If the value spikes or drops out
  Refer to: DTC P0102, P0103, U060F, or U1319
- Go to next step: If the value does not spike or drop out
Perform the following action:
1. Road test the vehicle.
2. Accelerate to wide open throttle until the transmission reaches the 1-2 shift.
  Verify DTC P0299 is not set.
- If the DTC sets
  Refer to: Circuit/System Testing
- Go to next step: If the DTC does not set
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
- If the DTC sets
  Refer to: Circuit/System Testing
- Go to next step: If the DTC does not set
All OK.