• | 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.
If the difference between the desired and actual engine speed is greater than a specified range, these DTCs will set.
• | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0336, P0351-P0358, P0401, P0403, P0404, P0405, P0406, P0440, P0442, P0443, P0446, P0452, P0453, P0496, P0502, P0503, P0601, P0604, P0606, P0641, P0651, P0722, P0723, P1516, P1680, P2101, P2120, P2122, P2123, P2127, P2128, P2135, P2138, P2176 are not set. |
• | The engine is operating for at least 60 seconds. |
• | The engine coolant temperature (ECT) is greater than -15°C (5°F). |
• | The intake air temperature (IAT) is greater than -18°C (0°F). |
• | The barometric pressure (BARO) is greater than 65 kPa. |
• | The system voltage is between 10.5-18 volts. |
• | The engine is at a stable idle for greater than 2 seconds. |
• | DTC P0506 and P0507 run continuously when the above conditions are met. |
• | The actual idle speed is approximately 100 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.
Throttle Actuator Control (TAC) System Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | Incorrect torque converter clutch (TCC) operation |
• | Accessories that require additional torque to operate |
• | Excessive deposits in the throttle body--Refer to Throttle Body Inspection and Cleaning . |
• | Restricted exhaust--Refer to Restricted Exhaust . |
• | Mechanical conditions that limit engine speed |
• | Vacuum leaks |
• | Unmetered air entering the engine, after the mass air flow |
• | A faulty positive crankcase ventilation (PCV) valve |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.