2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1868

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1868

Repair/Overhaul/102. Turbocharger Cleaning and Inspection).

5. 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. Inspect for any damage, restrictions, improper routing or connecting of the vacuum hoses on the charge air bypass solenoid valve and the

charge air bypass valve.

瀚慖f a condition is found, repair as necessary.

2. Clear the DTC and operate the vehicle within the Conditions for Running the DTC.

瀚慖f the DTC cannot be cleared or continues to reset, replace the charge air bypass valve.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Turbocharger Disassemble (See: Engine, Cooling and Exhaust/Engine/Service and Repair/Overhaul/101. Turbocharger Disassemble)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P2270

DTC P2270 (Without LF1)

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 Descriptor

DTC P2270

- HO2S Signal Stuck Lean Sensor 2

Circuit Description

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the low

reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the

exhaust is lean. The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine

the amount of time that the HO2S voltage was out of range. The ECM compares the stored HO2S voltage samples taken within each sample period

and determines if the majority of the samples are out of the operating range. The ECM test for the following conditions:

* The ECM monitors the HO2S voltage to determine if the signal voltage goes above a predetermined threshold within a certain amount of

time. If the ECM determines that the signal voltage remains below a threshold, the ECM will command the fuel system rich to determine if

the HO2S signal voltage can be forced above the threshold within a certain amount of time.

* The ECM monitors the HO2S voltage during power enrichment to ensure that the signal voltage goes above a predetermined threshold during

power enrichment.

Conditions for Running the DTC

* Before the ECM can report DTC P2270 failed, DTCs P0036, P0037, P0038, P0137, P0138, P0140, P0141, P0341, P0342, P0343, P0346,

P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P0443, P0458, and P0459 must run and pass.

* DTC P0461, P0462, P0463, P2066, P2067, or P2068 is not set.

* The engine is operating.

* The ignition voltage is greater than 10 V.

* The rear HO2S are at operating temperature for greater than 10 s.

* The long term fuel control is enabled.

* The mass air flow sensor is greater than 10 g/s.

* The MAF sensor is between 6-33 g/s for greater than 3 s during the intrusive test.

* DTC P2270 runs continuously when the above conditions are met for approximately 10 min when the fuel level is greater than 12 %.

* DTC P2270 runs continuously when the above conditions are met for approximately 20 min when the fuel level is less 12 %.