• | 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 | P0123 | P0068, P0121 |
TP Sensor 1 5-Volt Reference | P0122 | P2135 | P0122 | P0123 | -- |
TP Sensor 1 Low Reference | -- | P2135 | P0123 | -- | -- |
TP Sensor 2 Signal | P0222 | P2135 | P0223 | P0223 | P0068, P0121 |
TP Sensor 2 5-Volt Reference | P0222 | P2135 | P0222 | P0223 | -- |
TP Sensor 2 Low Reference | -- | P2135 | P0223 | -- | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Parameter Normal Range: 4.75-0.35 V | |||
TP Sensor 1 Signal | 0 V | 0 V | 5 V |
TP Sensor 1 5-Volt Reference | 0 V | 0 V | 5 V |
TP Sensor 1 Low Reference | -- | 5 V | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Parameter Normal Range: 0.35-4.65 V | |||
TP Sensor 2 Signal | 0 V | 5 V | 5 V |
TP Sensor 2 5-Volt Reference | 0 V | 0 V | 5 V |
TP Sensor 2 Low Reference | -- | 5 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 the following circuits:
• | A 5-volt reference circuit |
• | A low reference circuit |
• | A signal circuit |
Two processors are also used to monitor the TAC system data. Both processors are located within 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.
• | DTC P0601, P0602, P0603, P0604, P0606, P0607, P0641, P0651 are not set. |
• | The system voltage is more than 5.23 volts. |
• | The ignition is in the Unlock/Accessory or Run position. |
• | DTC P0120, P0122, P0123, P0220, P0222, P0223 run continuously when the above conditions are met. |
• | The system voltage is more than 5.23 volts. |
• | The ignition is in the Unlock/Accessory or Run position. |
• | DTC P0120, P0220, P0641, P0651 are not set. |
• | DTC P2135 runs continuously when the above conditions are met. |
TP sensor 1 voltage is less than 0.325 volt or more than 4.75 volts for more than 1 second.
The ECM detects that the TP sensor 1 voltage is less than 0.325 volt for more than 1 second.
The ECM detects that the TP sensor 1 voltage is more than 4.75 volts for more than 1 second.
The TP sensor 2 voltage is less than 0.25 volt or more than 4.59 volts for more than 1 second.
The ECM detects that the TP sensor 2 voltage is less than 0.25 volt for more than 1 second.
The ECM detects that the TP sensor 2 voltage is more than 4.59 volts for more than 1 second.
The difference between the TP sensor 1 and TP sensor 2 exceeds a predetermined value for more than 2 seconds.
• | 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. |
• | A message center or an 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
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If DTC P0120 or P0220 are the only DTCs set, replace the control module. |
⇒ | If DTC P0641 or P0651 is set, refer to DTC P0641 or P0651. |
⇒ | If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than 4.8 volts, test 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than 0.1 volt, test the signal circuit terminal D for a short to voltage. if the circuit tests normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the TP sensor 1 signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If the test lamp illuminates, test the TP sensor 2 signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than 1.0 volt, test the TP sensor 2 signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
• | ECM X2 signal circuit terminal 64 and the throttle body connector terminal D |
• | ECM X2 signal circuit terminal 66 and the throttle body connector terminal F |
• | ECM X2 5-volt reference circuit terminal 44 and the throttle body connector terminal E |
⇒ | If greater than 5 ohms, repair the affected circuit for open/high resistance. |
⇒ | If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuit. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming |