• | 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 | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
5-Volt Reference | P0122 | P0122 | P0122 | -- |
TP Sensor Signal | -- | P0122 | P0123 | -- |
Low Reference | -- | P0123 | -- | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: The engine is operating in closed loop. Parameter Normal Range: TP Position Sensor 5%/4.2 Volts | |||
5-Volt Reference | 6%/0.40 Volts | 6%/0.00 Volts | 14%/5.00 Volts |
TP Sensor Signal | 6%/0.00 Volts | 6%/0.00 Volts | 6%/5.00 Volts |
Low Reference | -- | 6%/5.00 Volts | -- |
The throttle body assembly contains a throttle position (TP) sensor. The TP sensor is mounted externally on the throttle body assembly. The TP sensor is a potentiometer which provides a signal voltage that changes relative to the throttle blade angle. The engine control module (ECM) supplies the TP sensor with a 5-volt reference circuit, a low reference circuit, and a signal circuit. The TP sensor signal voltage decreases from less than 1 volt at idle to more than 4 volts at wide open throttle (WOT).
• | The ignition is ON or the engine is operating. |
• | The DTCs run continuously once the above condition is met. |
Important: The scan tool displays a voltage near 0.0 volts. Do not use the scan tool voltage parameter to determine if there is a TP sensor condition.
The ECM detects that the TP sensor voltage is less than 0.14 volt for more than 5 seconds.
The ECM detects that the TP sensor voltage is more than 4.9 volts for more than 5 seconds.
DTC P0122 and P0123 are Type A DTCs.
DTC P0122 and P0123 are Type A DTCs.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
⇒ | If greater than 0.3 volt, test the signal circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM. |
Important: The test lamp is used to load the circuit and may not illuminate.
Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.
⇒ | If less than 4.8 volts, test the 5-volt reference circuit of the TP sensor for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM. |
⇒ | If greater than 5.2 volts, test the 5-volt reference circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM. |
⇒ | If greater than 0.2 volt, test the low reference circuit of the TP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM. |
⇒ | If greater than 5 ohms, test the low reference circuit of the TP sensor for an open/high resistance. If the circuit/connections test normal, replace the ECM. |
⇒ | If less than 4.8 volts, test the appropriate signal circuit of the TP sensor for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM. |
⇒ | If the resistance is not within the specified range, replace the TP sensor. |
⇒ | If the resistance is not within the specified range or is erratic, replace the TP sensor. |
⇒ | If the voltage is not within the specified range or is erratic, replace the TP sensor. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |