• | 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, P2127 | P0121, P0122, P0221, P2101, P2176 | P0223, P2101, P2138, P2128, P2119 | P0121, P0221 |
TP Sensor Signal 1 | P0122 | P0122 | P0123 | P0121 |
TP Sensor Signal 2 | P0222 | P0222 | P0223, P0638, P2128, P2138 | P0221 |
Low Reference | -- | P0121, P0123, P0221, P0223, P2176 | P0123, P0223* | P0121, P0221 |
* 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 V | |||
5-Volt Reference | 6 %/0.40 V | 6 %/0.00 V | 14 %/5.00 V |
TP Sensor Signal | 6 %/0.00 V | 6 %/0.00 V | 6 %/5.00 V |
Low Reference | -- | 6 %/5.00 V | -- |
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 increases from below 1 volt at idle to above 4 volts at wide open throttle (WOT). TP sensor 2 signal voltage decreases from above 4 volts at idle to below 1 volt at WOT.
• | The ignition 1 voltage is greater than 7 volts. |
• | The TP sensor 1 voltage is between 0.17-4.6 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 1 voltage is greater than 7 volts. |
• | DTC P0122 runs continuously once the above conditions are met. |
• | The ignition 1 voltage is greater than 7 volts. |
• | The TP sensor 2 voltage is between 0.15-4.8 volts. |
• | DTC P0221 runs continuously once the above conditions are met. |
The TP sensor 1 disagrees greater than 9 percent from TP sensor 2 Or TP sensor 1 disagrees greater than 9 percent from the predicted value. Either condition exists for greater than 4 seconds.
The ECM detects the TP sensor 1 signal voltage is less than 0.18 volts for greater than 4 seconds.
The ECM detects the TP sensor 1 signal voltage is greater than 4.6 volts for greater than 4 seconds.
The TP sensor 1 disagrees greater than 9 percent from TP sensor 2. Or TP sensor 2 disagrees greater than 9 percent from the predicted value. The above conditions are met for greater than 4 seconds.
The ECM detects the TP sensor 2 signal voltage is less than 0.16 volts for greater than 4 seconds.
The ECM detects the TP sensor 2 signal voltage is less than 0.16 volts for greater than 4 seconds.
DTCs P0121, P0122, P0123, P0221, P0222 and P0223 are type B DTCs.
DTCs P0121, P0122, P0123, P0221, P0222 and P0223 are type B 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.
• | Circuit Testing |
• | Wiring Repairs |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-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. |
Note: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
⇒ | If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If less than the specified range, test the 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 circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified value, test the signal circuit terminal D 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 terminal F for a short to ground. If the circuit tests normal, replace the ECM. |
Note: 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.
• | Engine Control Module Replacement for engine control module replacement, setup and programming |