P1516 - FAULT CODE - OBD2

P1516 ACURA, BUICK, CADILLAC, CHEVROLET, GMC, HUMMER, HONDA, ISUZU, SUZUKI: THROTTLE ACTUATOR CONTROL (TAC) MODULE THROTTLE ACTUATOR POSITION PERFORMANCE

The ECM (Engine Control Module) controls the TAC system (Throttle Actuator Control). The ECM determines the driver’s intention and based on this calculates the appropriate throttle response, which is achieved by a modulated pulse width voltage from the throttle body.

The TAC system uses the Throttle Body Engine Control (TAC) 1 and Throttle Body Motor Control (TAC) 2 circuits along with two processors to control the throttle body data. Both processors are located inside the ECM and are intended to monitor each other’s data to verify that the indicated throttle position is accurate.

If the showed throttle position is not similar to the expected throttle position within more than 0.5 s, the DTC code P1516 OBDII will be set.

• The Check Engine light turns on.
• A fixed speed during idling.
• It is not possible to accelerate the vehicle.

The reasons why the fault code P1516 OBD2 is stored are

• There may be damage to the Throttle Actuator Control Module (TAC) wiring.
• Water intrusion may occur at the CT
• Possibly, the throttle body is stuck.
• The Throttle Actuator Control may be in poor condition.

The steps to solve the P1516 OBDII diagnostic code are

• Check out the TSB.
• By using an automotive scanner, check if other DTCs are set. You must make the diagnosis of these following the order shown in the tool.
• Check for a condition in which the butterfly valve may have been held open. Ice may have formed in the throttle orifice during this time, causing the throttle valve to fail to close. Make the necessary corrections.
• Verify that the throttle body motor control circuit is not defective. If one of these shows corrosion or wear, make the appropriate repairs.
• Measure the CT circuit voltages and check that the ground and power signals are suitable. If you detect a short circuit, make the necessary repairs.