• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM commands the throttle plate open allowing more air to pass the throttle plate.
• | DTCs P0068, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0122, P0123, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0300, P0336, P0442, P0446, P0452, P0453, P0641, P0651, P1516, P2101, P2135, P2176 are not set. |
• | The engine is operating for at least 2 seconds. |
• | The engine coolant temperature (ECT) is more than -40°C (-40°F). |
• | The intake air temperature (IAT) is more than -40°C (-40°F). |
• | The barometric pressure (BARO) is more than 65 kPa. |
• | The system voltage is between 9-18 volts. |
• | The vehicle speed is less than 4.8 km/h (3 mph). |
• | DTC P0506 and P0507 run continuously when the above conditions are met. |
• | The actual idle speed is approximately 150 RPM lower than the desired idle speed. |
• | The above condition is present for 15 seconds. |
• | The actual idle speed is approximately 100 RPM greater than the desired idle speed. |
• | The above condition is present for 15 seconds. |
DTCs P0506 and P0507 are Type B DTCs.
DTCs P0506 and P0507 are Type B DTCs.
Control Module References for scan tool information
• | Actual engine idle speed should be no greater than 150 RPM below desired. |
• | Actual engine idle speed should be no greater than 100 RPM above desired. |
• | Incorrect torque converter clutch (TCC) operation |
• | Accessories that require additional torque to operate |
• | Excessive deposits in the throttle body |
• | Restricted exhaust |
• | Mechanical conditions that limit engine speed |
• | Vacuum leaks |
• | A faulty positive crankcase ventilation (PCV) valve |