Thursday, November 12, 2020

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2058

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2058

Circuit/System Description

Note: A new converter with less than 100 mi on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle

at highway speeds for approximately 1 h may correct the condition.

A 3-way catalytic converter controls emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The catalyst within

the converter promotes a chemical reaction, which oxidizes the HC and the CO that are present in the exhaust gas. This process converts the HC

and the CO into water vapor and carbon dioxide (CO2), and reduces the NOx, converting the NOx into nitrogen. The catalytic converter also stores

oxygen. The engine control module (ECM) monitors this process by using a heated oxygen sensor (HO2S) that is in the exhaust stream after the

3-way catalytic converter. The HO2S 2 produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This

indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by allowing the

catalyst to heat, then wait for a stabilization period while the engine is idling. The ECM then adds and removes fuel while monitoring the HO2S 2.

When the catalyst is functioning properly, the HO2S 2 response to the extra fuel is slow compared to the response of the HO2S 1, which is located

before the 3-way catalytic converter. When the HO2S 2 response is near that of the HO2S 1, the oxygen storage capability and efficiency of the

catalyst may be degraded below an acceptable threshold.

Conditions for Running the DTC

* DTCs P0030, P0031, P0036, P0037, P0038, P0068, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123,

P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0171, P0172, P0201, P0202, P0203,

P0204, P0205, P0206, P0207, P0208, P0220, P0300, P0315, P0326, P0327, P0336, P0340, P0341, P0442, P0446, P0452, P0453, P0455,

P0496, P0500, P0502, P0506, P0507, P0601, P0602, P0606, P0641, P0722, P0723, P1133, P1134, P1516, P1621, P2135, P2138, P2176 are

not set.

* Before the ECM performs the idle test, the vehicle must be driven under the following conditions:

- The engine speed is greater than 1,300 RPM.

- The engine run time is greater than 100 s.

- Both conditions exist for greater than 16 s.

* The vehicle speed is less than 1.6 km/h (1 mph).

* The throttle position is less than 2 %.

* The mass air flow (MAF) is between 2-21 g/s.

* The engine is operating in Closed Loop.

* The fuel trim learn is enabled.

* The engine coolant temperature (ECT) is between 45-129掳C (113-264掳F).

* The barometric pressure (BARO) is greater than 70 kPa.

* The Catalytic Converter Calculated Temperature parameter is between 600-900掳C (1,112-1,652掳F) for greater than 6 min.

* The intake air temperature (IAT) is between -20 and +250掳C (-4 and +482掳F).

* The battery voltage is greater than 11 V.

* The transmission is in Drive Range-Automatic transmissions only.

* The short term fuel trim is between -10 and +10 %.

* The engine is idling for less than 50 s.

* This diagnostic attempts one test during each valid idle period when the above conditions have been met. This diagnostic attempts up to 8

tests during each drive cycle.

Conditions for Setting the DTC

The ECM has determined the catalyst efficiency has degraded below a calibrated threshold.

Action Taken When the DTC Sets

DTCs P0420 and P0430 are Type A DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0420 and P0430 are Type A DTCs.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Electrical Information Reference

Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle)

Circuit/System Verification

1. Verify that no other DTCs are set.

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