Sunday, December 22, 2019

2010 Cadillac Truck Escalade AWD V8-6.2L Page 2530

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure. Verify the repair under the same

speed and load as noted in the Freeze Frame/Failure Records data recorded during testing.


DTC P1174 or P1175

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 Descriptors

DTC P1174

- Fuel Trim Cylinder Balance Bank 1

DTC P1175

- Fuel Trim Cylinder Balance Bank 2

Circuit/System Description

The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance in each bank. The diagnostic monitors

the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a

predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired


Conditions for Running the DTC

* DTCs P0030, P0036, P0050, P0053, P0059, P0101, P0102, P0103, P0106, P0107, P0108, P0117, P0118, P0128, P0131, P0132, P0133,

P0134, P0135, P0151, P0152, P0153, P0154, P0155, P0201-P0206, P0300, P0301-P0306, P0411, P0412, P0418, P0442, P0443, P0446,

P0449, P0452, P0453, P0454, P0455, P0496, P1133, P1153, P1516, P2101, P2119, P2120, P2125, P2135, P2138, P2176, P2431, P2432,

P2433, P2440, P2A00, P2A03 are not set.

* The device control is not active.

* The intrusive diagnostics are not active.

* The engine overspeed protection is not active.

* The power take-off (PTO) is not active.

* The traction control is not active.

* The fuel control is in air-fuel Closed Loop.

* The system voltage is more than 10 volts, or less than 18 volts.

* The engine run time is greater than 100 seconds.

* The engine coolant temperature (ECT) is greater than -20锟斤拷C (-4锟斤拷F).

* The engine speed is greater than 425 RPM, but less than 6,000 RPM.

* The mass air flow is greater than 25 g/s, but less than 510 g/s.

Conditions for Setting the DTC

Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

Action Taken When the DTC Sets

DTCs P1174 and P1175 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P1174 and P1175 are Type B DTCs.

Diagnostic Aids

* The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part

number may set a false DTC.

* Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.

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