2010 Cadillac CTS Sedan AWD V6-3.6L Page 1942
瀚慖f DTC P2227, P2228, or P2229 sets, replace the K20 ECM.
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for engine control module replacement, setup, and
DTC P2227, P2228, or P2229 (LLT)
* 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.
- Barometric Pressure (BARO) Sensor Performance
- Barometric Pressure (BARO) Sensor Circuit Low Voltage
- Barometric Pressure (BARO) Sensor Circuit High Voltage
The barometric pressure (BARO) sensor responds to changes in altitude and atmospheric conditions. This gives the engine control module (ECM)
an indication of barometric pressure. The ECM uses this information to calculate fuel delivery. The BARO sensor is located within the controller
and is not serviced as a separate unit. The BARO sensor provides a voltage signal to the ECM relative to the atmospheric pressure changes. The
ECM monitors the BARO sensor signal for a voltage outside of the normal range.
Conditions for Running the DTC
* Before the ECM can report DTC P2227 failed, DTCs P0100, P0101, P0102, P0103, P0121, P0122, P0123, P0221, P0222, P0223, P2228,
and P2229 must run and pass.
* The engine is operating for greater than 1 s.
* The mass air flow sensor signal is valid.
* The evaporative emission (EVAP) leak test is not enabled.
* DTC P2227 runs continuously once the above conditions are met for 2 s.
P2228 or P2229
* The engine is operating.
* The DTCs run continuously once the above conditions are met for 2 s.
Conditions for Setting the DTC
* The ECM detects that the BARO pressure is less than 50 kPa or greater than 115 kPa and DTC P2228 or P2229 is not set.
* The ECM detects that the BARO pressure changed greater than 10 kPa within 20 s.
* The ECM detects that the BARO pressure changed greater than 30 kPa since the last ignition cycle, and the difference between the BARO
signal and the calculated BARO is greater than 2 kPa. The condition exists within 1 s of engine start up.
* DTC P2227 sets if any of the conditions above exist for greater than 1 s.
The ECM detects that the BARO sensor voltage is less than 0.20 V for 1 s.