2010 Cadillac Truck SRX FWD V6-3.0L Page 1385

2010 Cadillac Truck SRX FWD V6-3.0L Page 1385

DTC P0302

- Cylinder 2 Misfire Detected

DTC P0303

- Cylinder 3 Misfire Detected

DTC P0304

- Cylinder 4 Misfire Detected

DTC P0305

- Cylinder 5 Misfire Detected

DTC P0306

- Cylinder 6 Misfire Detected

Circuit/System Description

The engine control module (ECM) uses information from the crankshaft position sensor and the camshaft position sensors in order to determine

when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect

individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL)

will flash ON and OFF when the conditions for catalytic converter damage are present. DTCs P0301 through P0306 correspond to cylinders 1

through 6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set, and the corresponding fuel

injector is disabled. The ECM will re-enable the fuel injector after 4 crankshaft revolutions when the misfire is not current. The ECM will re-enable

the fuel injector after 8 crankshaft revolutions when the misfire is not current, if the vehicle is equipped with a manual transmission.

Conditions for Running the DTC

* DTC P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0068, P0101, P0102, P0103, P0106,

P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651,

P1516, P2101, P2122, P2123, P2127, P2128 or P2176 is not set.

* The engine speed is between 450-6,600 RPM.

* The evaporative emissions (EVAP) leak detection is not active.

* The delivered torque signal is greater than 5 % at idle.

* The delivered torque signal is between 6-29 % with the transmission in drive.

* The engine coolant temperature (ECT) is between -7 and +127掳C (+19 and +261掳F).

* The ECM is not receiving a rough road signal.

* The fuel level is greater than 11 %.

* The antilock brake system (ABS) and the traction control system (TCS) are not active or detecting rough road.

* Torque Converter Clutch (TCC) is not applied/active.

* The ECM is not in fuel cut-off or decel fuel cut-off mode.

* DTCs P0300 through P0306 run continuously when the above conditions exist for greater than 1,000 engine revolutions. 200 revolutions

after the first failure.

Conditions for Setting the DTC

P0300

The ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed a predetermined value.

P0301, P0302, P0303, P0304, P0305, P0306

The ECM detects a crankshaft rotation speed variation indicating a single cylinder misfire rate sufficient to cause emissions levels to exceed

mandated standards.

Action Taken When the DTC Sets

* DTCs P0300-P0306 are Type B DTCs.

* The ECM disables the fuel injector of the misfiring cylinder when a misfire is present.

Conditions for Clearing the DTC

DTCs P0300-P0306 are Type B DTCs.

Diagnostic Aids

* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources:

- A tire or wheel that is out of round or out of balance

- Variable thickness brake rotors