Circuit/System Verification
WARNING: This page is about a different variant/trim than selected.
- Ignition - On/Vehicle - In Service Mode
- Verify there are no DTCs set related to the following component/system:
- 5V Reference Circuit
- B74 Manifold Absolute Pressure Sensor - Circuit DTCs
- B75 Mass Air Flow Sensor - Circuit DTCs
- Q38 Throttle Body - Circuit DTCs@Throttle Position Sensor
- If a related DTC is set
- Go to next step: If a related DTC is not set
- Verify the scan tool parameter: Throttle Body Idle Air Flow Compensation = Less than 90%
- If 90% or greater
Refer to: Throttle Body Inspection and Cleaning
- Go to next step: If less than 90%
- If 90% or greater
- Perform the scan tool control function: Throttle Sweep - Start
Verify the scan tool parameter: Throttle Position Sensors 1 and 2 = Agree
- If not the specified state
Refer to: DTC P0122, P0123, P0222, P0223, P2135, U0606, or U0607
- Go to next step: If the specified state
- If not the specified state
- Verify the scan tool parameter: MAP Sensor = The value should be within the range listed in the table: Altitude Versus Barometric Pressure
- If not in the specified range
Refer to: DTC P0107 or P0108
- Go to next step: If in the specified range
- If not in the specified range
- Perform the following procedure/test: Component/System Leak Test
Verify the procedure/test passes.
- If the procedure/test does not pass
Repair or replace as necessary
- Go to next step: If the procedure/test passes
- If the procedure/test does not pass
- Verify the following conditions do not exist:
- B74 Manifold Absolute Pressure Sensor - Visible Damage
- B75C Multifunction Intake Air Sensor - Contamination of the measuring element/Cracked/ Visible Damage/Water intrusion
- Q38 Throttle Body
- Coking/ Visible Damage
- Ice/Moisture/Restricted
- Air Cleaner Element - Dirty/Restricted
- Exhaust System/Catalytic Converter - Restricted/ Visible Damage - Refer to: Symptoms - Engine Exhaust
- Intake Air Duct - Restricted/Visible Damage
- Intake Manifold - Restricted/Vacuum leak/Visible Damage
- Positive Crankcase Ventilation System
- Ice/Moisture/Restricted
- Incorrect connection
- Vacuum Hoses - Incorrect connection/Kinked/ Restricted
- Vacuum leak @ Engine - Oil Level Indicator and Tube/Oil Filler Cap
- If a condition exists
Repair or replace the components as necessary.
- Go to next step: If no condition exists
- Verify the following conditions do not exist: Engine - Mechanical Condition
- Camshaft Lobe(s) - Visible Damage/Worn
- Exhaust Valve or Intake Valve - Stuck Open/Visible Damage
- Exhaust Valve Seat or Intake Valve Seat - Visible Damage
- Piston - Cracked/Visible Damage
- Piston Ring - Seized/Visible Damage/Worn
NOTE:The list is not all encompassing - Refer to: Symptoms - Engine Mechanical
- If a condition exists
Repair or replace as necessary
- Go to next step: If no condition exists
- Engine - Idling - At normal operating temperature
- Verify the scan tool parameter:
- MAP Sensor = 26 to 52 kPa (3.8 to 7.5 PSI) @Idle Speed
- MAP 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
- 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: MAF Sensor
Verify the scan tool parameter: MAF Sensor = The value should not spike or drop out.
- If the value spikes or drops out
Refer to: DTC P0102 or P0103
- Go to next step: If the value does not spike or drop out
- If the value spikes or drops out
- 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
Repeat the procedure starting at step 2
- Go to next step: If the DTC is not set
- If the DTC sets
- All OK.