Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Check Throttle Actuator Control (TAC) module connector for water– Binding or bent

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Throttle plate sticking due to carbon build-up– Engine Control Module When is

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection– Throttle plate sticking due to carbon build-up– Engine Control Module When is

Possible causes – Faulty Throttle Actuator Control (TAC) module– Throttle Actuator Control (TAC) module harness is open or shorted– Throttle Actuator Control (TAC) module circuit poor electrical connection When is the code detected? The Engine Control Module (ECM) has detected

Possible causes – Faulty Throttle Position Sensor– Throttle Position Sensor harness is open or shorted– Throttle Position Sensor circuit poor electrical connection– Throttle Position Sensor not properly adjusted When is the code detected? When the Powertrain Control Module (PCM) senses

Possible causes – Faulty Throttle Position Sensor– Throttle Position Sensor harness is open or shorted– Throttle Position Sensor circuit poor electrical connection– Throttle Position Sensor not properly adjusted When is the code detected? When the Powertrain Control Module (PCM) senses

Possible causes – Faulty Throttle Position Sensor– Throttle Position Sensor harness is open or shorted– Throttle Position Sensor circuit poor electrical connection– Throttle Position Sensor not properly adjusted When is the code detected? When the Powertrain Control Module (PCM) senses

Possible causes – Faulty Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid– Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid harness is open or shorted– Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid circuit poor electrical connection

Possible causes – Faulty Wheel Speed Sensor– Wheel Speed Sensor harness is open or shorted– Wheel Speed Sensor circuit poor electrical connection When is the code detected? The Engine Control Module (ECM) detects an invalid rough road signal from the

Possible causes – Fualty ECM– Wrong ECM for vehicle– Service program error When is the code detected? Engine Control Module (ECM) program does not recognize the vehicles id, or the id is missing in the ECM. Symptoms – Engine Light

Possible causes – High fuel pressure– Leaking fuel injector or pressure regulator– Failed Mass Air Flow (MAF) sensor When is the code detected? The Engine Control Module (ECM) has detected a rich air/fuel ratio Symptoms – Engine Light ON (or

Possible causes – Idle Air Control Valve harness is open or shorted– Idle Air Control Valve circuit poor electrical connection– Faulty Idle Air Control Valve Symptoms – Engine Light ON (or Service Engine Soon Warning Light)– Engine rough idle

Possible causes – Leaking fuel pressure regulator– Leaking fuel injector When is the code detected? The average long term fuel trim values at idle are less than -30 percent for 10 seconds Symptoms – Engine Light ON (or Service Engine

Possible causes – Low transmission fluid level – Dirty or contaminated fluid – Internal transmission failure When is the code detected? When the Powertrain Control Module (PCM) detects excessive Torque Converter Clutch (TCC) slip when the TCC should be engage,

Possible causes – Poor connection at the Throttle Actuator Control (TAC) module– Faulty TAC module– Faulty Throttle Pedal Position (TPP) or Throttle Position (TPS) sensors– Binding or bent throttle plate-failed throttle body When is the code detected? The Powertrain Control

Possible causes – Pressure Control Solenoid harness is open or shorted– Pressure Control Solenoid circuit poor electrcial connection – Faulty Control Solenoid Valve Assembly When is the code detected? The Transmission Control Module (TCM) has detected an internal low voltage

Possible causes – Repair other codes first Tech notes If the P1380 code is set with other codes, repair other codes first and then clear the code. When is the code detected? If the Electronic Brake Control Module (EBCM) detects

Possible causes – Repair other codes first Tech notes If the P1381 code is set with other codes, repair other codes first and then clear the code. When is the code detected? If a loss of communication occurs which causes

Possible causes – Reprogram TCM and recheck code– Replace Transmission Control Module (TCM) Sensor/body assembly one piece Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1684 CHEVROLET Description The Transmission Control Module (TCM) power up the temperature

Possible causes – Reprogram TCM and recheck code– Replace Transmission Control Module (TCM) Sensor/body assembly one piece Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1685 CHEVROLET Description The Transmission Control Module (TCM) power up the temperature