• | 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. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
TP Sensor 1 Signal | P0122 | P2135 | P0122, P2135 | P0123 | P0068, P0120, P0121 |
TP Sensor 2 Signal | P0222 | P2135 | P0223, P2125 | P0223 | P0068, P0121, P0220 |
Throttle Position Sensor 1 and 25 V Reference | P0651 | P2135 | P0122, P0222 | P0651 | -- |
Throttle Position Sensor 1 and 2 Low Reference | -- | P2135 | P0123, P0223 | -- | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: With the engine running, turn the ignition ON Parameter Normal Range: 4.20-0.5 V | |||
Throttle Position Sensor 1 and 25 V Reference | 0.04 V | 0.00 V | 4.98 V |
TP Sensor 1 Signal | 0.00 V | 0.00 V | 4.98 V |
Throttle Position Sensor 1 and 2 Low Reference | -- | 4.98 V | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: With the engine running, turn the ignition ON Parameter Normal Range: 0.7-4.5 V | |||
Throttle Position Sensor 1 and 25 V Reference | 0.04 V | 0 V | 3.63 V |
TP Sensor 2 Signal | 0.00 V | 4.98 V | 4.98 V |
Throttle Position Sensor 1 and 2 Low Reference | -- | 4.98 V | -- |
The throttle actuator control (TAC) system uses 2 throttle position (TP) sensors to monitor the throttle position. The TP sensors 1 and 2 are located within the throttle body assembly. Each sensor has a signal circuit and share a 5-volt reference and low reference circuit.
Two processors are also used to monitor the TAC system data. Both processors are located in the engine control module (ECM). Each signal circuit provides both processors with a signal voltage proportional to throttle plate movement. Both processors monitor each other's data to verify that the indicated TP calculation is correct.
• | DTCs P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, P0651 are not set. |
• | System voltage is greater than 5.23 volts. |
• | The ignition switch is in Unlock/Accessory, Run or Crank. |
• | DTCs P0120, P0122, P0123, P0222, P0223, and P2135 run continuously when the above conditions are met. |
• | The TP sensor 1 voltage is less than 0.33 volt or more than 4.75 volts. |
• | It occurs 79 times or 52 times continuously during the 159 tests. |
• | The engine control module (ECM) detects the TP sensor voltage is less than 0.33 volt. |
• | It occurs 79 times or 52 times continuously during the 159 tests. |
• | The ECM detects the TP sensor 1 voltage is more than 4.58 volts. |
• | It occurs 79 times or 55 times continuously during the 159 tests. |
• | The TP sensor 2 voltage is less than 0.25 volt or more than 4.59 volts. |
• | It occurs 79 times or 52 times continuously during the 159 tests. |
• | The ECM detects the TP sensor 2 voltage is less than 0.25 volt. |
• | It occurs 79 times or 52 times continuously during the 159 tests. |
• | The ECM detects the TP sensor 2 voltage is more than 4.59 volts. |
• | It occurs 79 times or 52 times continuously during the 159 tests. |
• | The voltage differences between the TP sensor 1 and TP sensor 2 exceeds the predetermined value. |
• | It occurs 79 times or 63 times continuously during the 159 tests. |
• | DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs. |
• | The control module commands the TAC system to operate in the Reduced Engine Power mode. |
• | The message center or the indicator displays Reduced Engine Power. |
• | Under certain conditions the control module commands the engine OFF. |
DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.
Throttle Actuator Control (TAC) System Description
Diagnostic Trouble Code (DTC) Type Definitions
⇒ | If only DTC P0120 or P0220 are set, and all of the previous TP sensor parameters are normal, replace the ECM. |
⇒ | If DTC P0641 or P0651 is set, refer to DTC P0641 or P0651 . |
⇒ | If more than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit test normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the ECM. |
⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for short to voltage. If the circuit test normal, replace the ECM. |
⇒ | If greater than 0.1 volt, test the signal circuit terminal D for a short to voltage. If the circuit test normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the signal circuit for a short to ground. If the circuit test normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the TP sensor 1 signal circuit for short to ground or an open/high resistance. If the circuit test normal, replace the ECM. |
⇒ | If greater than 0.1 volt, test the TP sensor 2 signal circuit for a short to voltage or an open/high resistance. If the circuit test normal, replace the ECM. |
• | ECM C2 signal circuit terminal 64 to TP terminal D |
• | ECM C2 signal circuit terminal 68 to TP terminal F |
• | ECM C2 5-volt reference circuit terminal 44 to TP terminal E |
⇒ | If greater than 5 ohms, repair the affected circuit. |
⇒ | If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuits. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |