2010 Cadillac CTS Sedan AWD V6-3.6L Page 933
* 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 P0506
- Idle Speed Low
DTC P0507
- Idle Speed High
DTC P050A
- Cold Start Idle Air Control System Performance
Circuit/System Description
The throttle actuator control (TAC) motor is a DC motor that is part of the throttle body assembly. The TAC motor drives the throttle valve. The
engine control module (ECM) controls the TAC motor based on throttle position sensor input. The idle speed is controlled by the ECM based on
various inputs. The ECM commands the TAC motor to open or close the throttle valve in order to maintain the desired idle speed. If the ECM
detects the actual idle speed is not within a predetermined range of the desired idle speed, this DTC sets.
Conditions for Running the DTC
P0506 and P0507
* DTC P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0221, P0222, P0223, P0442, P0443, P0446, P0455,
P0458, P0459, P0496, or P0700 is not set.
* The engine is operating for greater than 4 seconds.
* The engine load is between 32-75 percent, for P0506 or manual transmission only.
* The engine coolant temperature (ECT) is warmer than -11掳C (+13掳F).
* The intake air temperature (IAT) is warmer than -11掳C (+13掳F).
* The vehicle speed is 0 km/h (0 mph) and accelerator pedal position (APP) input is at 0 percent.
* The EVAP intrusive leak test is not enabled.
* The cold start idle speed control is not active.
* The evaporative emission (EVAP) canister purge valve command less than 40 percent.
* A vehicle speed was detected prior to the diagnostic running.
* DTC P0506 and P0507 run continuously once the above conditions are met for greater than 10 seconds.
P050A
* DTC P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0221, P0222, P0223, P0442, P0443, P0446, P0455,
P0458, P0459, P0496, or P0700 is not set.
* The engine load is between 70-90 percent, for under speed or manual transmission only.
* The vehicle speed is 0 km/h (0 mph) and accelerator pedal position (APP) input is at 0 percent.
* The engine coolant temperature (ECT) is colder than 65掳C (149掳F).
* The catalyst cold start heating strategy is active.
* DTC P050A runs once an ignition cycle when the conditions above have been met for 7 seconds.
Conditions for Setting the DTC
P0506
The actual engine speed is less than the desired idle speed by at least 100 RPM for greater than 4 seconds.
P0507
* The actual engine speed is greater than the desired idle speed by at least 200 RPM for greater than 4 seconds.
OR
* The ECM detects 3 fuel cut-offs due to an engine over speed condition while the vehicle speed is zero.
P050A
The actual engine speed is 100 RPM less or 200 RPM greater than the desired idle speed during a cold start, for greater than 4 seconds.
Action Taken When the DTC Sets
DTCs P0506, P0507, and P050A are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0506, P0507, and P050A are Type B DTCs.
