2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2425
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.
P1175
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
value.
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掳C (-4掳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.
