The electronic throttle control (ETC) system uses various inputs from the powertrain control module (PCM) in order to control the idle speed through serial data circuits to the throttle actuator control (TAC) module. The DC motor located on the throttle body actuates the throttle plate. In order to decrease idle speed, the TAC module commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the TAC module commands the throttle plate open allowing more air to bypass the throttle plate. If the actual idle RPM does not match the desired idle RPM within a calibrated time, this diagnostic trouble code (DTC) will set.
• | DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0125, P0171, P0172, P0174, P0175, P0200, P0300, P0440, P0442, P0443, P0500, P0502, P0503, P1120, P1220, P1221, or P1441 are not set. |
• | The engine is operating for greater than 60 seconds. |
• | The engine control temperature (ECT) is greater than 60°C (140°F). |
• | The intake air temperature (IAT) is greater than -10°C (+14°F). |
• | The barometric pressure (BARO) is greater than 65 kPa. |
• | The system voltage is between 9-18 volts. |
• | The vehicle speed is less than 1.7 km/h (1 mph). |
• | The accelerator pedal position (APP) indicated angle is 0 percent. |
• | The actual idle speed is 200 RPM more than the desired idle speed. |
• | All of the above conditions present for 5 seconds. |
• | The control module stores the DTC information into memory when the diagnostic runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
• | The driver information center, if equipped, may display a message. |
• | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
• | Clear the DTC with a scan tool. |
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No | ||||
---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||||||
1 | Did you perform a Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||
Did the engine speed stay within 200 RPM of the commanded RPM during the above test? | Go to Step 3 | Go to Step 4 | |||||
3 |
Does the DTC reset? | Go to Step 4 | Go to Intermittent Conditions | ||||
4 | Inspect for the following conditions:
Did you complete the repair? | Go to Step 5 | -- | ||||
5 |
Does the DTC run and pass? | Go to Step 6 | Go to Step 2 | ||||
6 | Use a scan tool in order to observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | System OK |