P1120

CIRCUIT DESCRIPTION
The throttle position (TP) sensor is mounted on the throttle body assembly. The sensor is actually two individual TP sensors within one housing. Two separate signal, low reference, and 5-volt reference circuits are used in order to connect the TP sensor assembly to the throttle actuator control (TAC) module. The 2 sensors have opposite functionality. The TP sensor 1 signal voltage is pulled up to reference voltage as the throttle opens, from less than 1 volt at closed throttle to more than 3.5 volts at wide open throttle (WOT). The TP sensor 2 signal voltage is pulled down to low reference from around 3.8 volts at closed throttle to less than 1 volt at WOT. TP sensor 1 and accelerator pedal position (APP) sensor 1 share a 5-volt reference circuit that is connected within the TAC module. TP sensor 2 and APP sensor 2 share a 5-volt reference circuit that is connected within the TAC module. If an out-of-range condition is detected with the TP sensor 1, this DTC will set and the Reduced Engine Power message will be displayed.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P1517 and P1518 are not set.
^ The ignition switch is in the crank or run position.
^ The ignition voltage is greater than 5.23 volts.

CONDITIONS FOR SETTING THE DTC
^ The TP sensor 1 signal voltage is less than 0.13 volts or greater than 4.87 volts.
^ All of the above conditions exist for less than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
^ The control module commands the TAC system to operate in the Reduced Engine Power mode.

OR

^ Under certain conditions the control module commands the engine OFF.
^ The message center displays Reduced Engine Power.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
^ Inspect the TAC module connectors for signs of water intrusion. When this condition occurs, multiple DTCs could be set without circuit or component conditions found during diagnostic testing.
^ When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Be aware of this if you review the stored information in Capture Info.
^ If this DTC is determined to be intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-7:

Steps 8-16:

Steps 17-26:

Steps 27-32:

The number below refers to the step number on the diagnostic table.
32. When the TAC module detects a condition within the TAC system, more than one TAC system-related DTC may set. This condition is due to the many redundant tests that continuously run on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Be aware of this if you review the stored information in Capture Info.