• | 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, P0222 | P0121, P0122, P0221, P0222, P2119, P2101 | P0123, P0223, P2101, P2119 | P0121, P0221 |
TP Sensor Signal 1 | P0122 | P0121, P0122, P2101, P2119 | P0123 | P0121, P0221, P2119 |
TP Sensor Signal 2 | P0222 | P0221, P0223 | P0223, P0638, P2128, P2138 | P0221 |
Low Reference | -- | P0121, P0123, P0221, P0223, P2119, P2100 | P0123, P0223¹ | P0121, P0221 |
¹ Internal ECM or TP sensor damage may occur if the circuit is shorted to B+ |
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 | 124%/0.0 Volts | 7%/0.0 Volts | 113%/TP 1 4.98, TP 2, 4.50 Volts |
TP Sensor Signal 1 | 4%/0.00 Volts | 7%/0.00 Volts | 7%/0.00 Volts |
TP Sensor Signal 2 | 4%/0.00 Volts | 4%/4.98 Volts | 27%/4.98 Volts |
Low Reference | -- | 0%/4.98 Volts | -- |
The throttle body assembly contains 2 throttle position (TP) sensors. The TP sensors are mounted to the throttle body assembly and are not serviceable. The TP sensors provide a signal voltage that changes relative to throttle blade angle. The engine control module (ECM) supplies the TP sensors with a common 5-volt reference circuit , a common low reference circuit, and two independent signal circuits. The TP sensors have opposite functionality . TP sensor 1 signal voltage decreases from greater than 4 volts at idle to less than 1 volt at wide open throttle (WOT). TP sensor 2 signal voltage increases from less than 1 volt at idle to greater than 4 volts at WOT.
• | The ignition voltage is more than 7 volts. |
• | The TP sensor 1 voltage is between 0.18-4.6 volts. |
• | DTC P0121 runs continuously once the above conditions are met. |
• | The ignition is ON, with the engine OFF, or the engine is operating. |
• | The ignition voltage is more than 7 volts. |
• | DTC P0122 runs continuously once the above conditions are met. |
• | The ignition voltage is more than 7 volts. |
• | The TP sensor 2 voltage is between 0.16-4.9 volts. |
• | DTC P0221 runs continuously once the above conditions are met. |
The TP sensor 1 disagrees more than 6 percent from TP sensor 2 for greater than 0.14 second, and TP sensor 1 disagrees more than 9 percent from the predicted value for greater than 0.24 second.
The ECM detects the TP sensor 1 signal voltage is less than 0.18 volt for greater than 0.14 second.
The ECM detects the TP sensor 1 signal voltage is more than 4.6 volts for greater than 0.14 second.
The TP sensor 1 disagrees more than 6 percent from TP sensor 2 for greater than 0.14 second, and TP sensor 2 disagrees more than 9 percent from the predicted value for greater than 0.24 second.
The ECM detects the TP sensor 2 signal voltage is less than 0.16 volt for greater than 0.14 second.
The ECM detects the TP sensor 2 signal voltage is greater than 4.9 volts for greater than 0.14 second.
• | DTCs P0121 and P0221 are Type B DTCs. |
• | DTCs P0122, P0123, P0222, and P0223 are Type A DTCs. |
• | DTCs P0121 and P0221 are Type B DTCs. |
• | DTCs P0122, P0123, P0222, and P0223 are Type A DTCs. |
If there is a condition with the TP sensors the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
⇒ | If a DTC is set, refer to DTC P0698 or P0699 . |
• | Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. |
• | Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. |
• | The TP sensor 1 and 2 parameter should display Agree. |
Important: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
⇒ | If greater than the specified value, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
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 the specified range, test the 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 the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified value, test the signal circuit for an open/high resistance or for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
Important: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage.
⇒ | If greater than the specified value, test the signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal, replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |