DTC P1125 Without RPO CTF
| Table 1: | APP Sensor Position Table |
| Table 2: | DTC P1125 APP System |
Circuit Description
The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within one housing. Three separate signal, low reference, and 5-volt reference circuits are used in order to interface the APP sensor with the ECM. Each sensor has a unique fuctionality to determine pedal position as shown in the table below. The engine control module (ECM) uses the APP sensor to determine the amount of acceleration or deceleration desired by the person driving the vehicle via fuel injector control. This diagnostic trouble code (DTC) sets if the ECM detects a condition with more than one sensor within the APP sensor.
APP Sensor | Actual Pedal Position | % Depressed as Observed on a Scan Tool | Voltage as Observed on a Scan Tool |
|---|---|---|---|
1 | Pedal at rest | 0 | 0.53-0.78 |
1 | Pedal at full travel | 100 | 0.39-2.64 |
2 | Pedal at rest | 0 | 4.22-4.47 |
2 | Pedal at full travel | 100 | 2.36-2.61 |
3 | Pedal at rest | 0 | 3.86-4.13 |
3 | Pedal at full travel | 100 | 2.75-3.00 |
Conditions for Running the DTC
| • | The ignition switch is in the crank or run position. |
| • | The ignition voltage is between 7-16 volts. |
Conditions for Setting the DTC
| • | The ECM detects a condition with more than one APP sensor. |
| • | All of the above conditions present for less than 1 second. |
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | If one or more APP sensor DTCs are set for a single APP sensor, the control module will use the remaining two APP sensors to calculate throttle response. |
| • | If certain multiple APP sensor DTCs are set for more than one APP sensor, the APP indicated angle is limited to a predetermined value to limit the amount of throttle control. |
| • | If all three APP sensors are out of range, the APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | Clear the DTC with a scan tool. |
Diagnostic Aids
| • | APP sensor 1 and APP sensor 3, 5-volt reference circuits are internally connected within the ECM. |
| • | The APP sensor 2, 5-volt reference circuit is shared with the barometric pressure (BARO) sensor and the turbo boost solenoid and they are internally connected within the ECM. |
| • | For an intermittent, refer to Intermittent Conditions . |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | |
2 | Is DTC P0641 set? | Go to DTC P0641 | Go to Step 3 |
3 | This DTC indicates that two or more APP sensor DTCs are set. Are other APP sensor DTCs set? | -- |
DTC P1125 With RPO CTF
| Table 1: | APP Sensor Position Table |
Circuit Description
The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. The sensor is made up of 3 individual sensors within one housing.
The APP sensor 1, 2 and APP sensor 3 are potentiometer type sensors, each with the following circuits:
| • | A 5-volt reference circuit |
| • | A low reference circuit |
| • | A signal circuit |
The engine control module (ECM) provides the APP sensors a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the ECM signal voltages proportional to pedal movement. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed. The APP sensor 2 signal voltage is high at rest and decreases as the pedal is depressed. The APP sensor 3 signal voltage is high at rest and decreases as the pedal is depressed. If the ECM detects two or more APP open, this DTC will set.
Conditions for Running the DTC
| • | The ignition switch is ON. |
| • | The ignition voltage is between 7-16 volts. |
Conditions for Setting the DTC
Two or three sensor signals contain an open circuit.
Action Taken When the DTC Sets
| • | The ECM illuminates the malfunction indicator lamp (MIL) and reduced engine power indicator lamp, if fitted, when the diagnostic runs and fails. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
| • | The ECM inhibits cruise control. |
| • | The ECM inhibits power take-off (PTO) control. |
Conditions for Clearing the DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
If an intermittent condition is suspected, the following may cause an intermittent:
| • | Poor connections |
| • | Misrouted harness |
| • | Rubbed through wire insulation |
| • | Broken wire inside the insulation |
Inspect for the following conditions:
| • | Poor connection at ECM--Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness appears to be OK, observe the DTC P1125 display on the scan tool while moving connectors and wiring harness related to the sensor. A change in the display will indicate the location of the fault. |
APP Sensor | Actual Pedal Position | % Depressed as Observed on a Scan Tool | Voltage as Observed on a Scan Tool |
|---|---|---|---|
1 | Pedal at rest | 0 | 0.52-0.80 |
1 | Pedal at full travel | 100 | 2.38-2.66 |
2 | Pedal at rest | 0 | 4.20-4.48 |
2 | Pedal at full travel | 100 | 2.34-2.62 |
3 | Pedal at rest | 0 | 3.92-4.09 |
3 | Pedal at full travel | 100 | 2.79-2.96 |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | |
2 | Is DTC P0641 or P0651 also set? | Go to Step 3 | |
3 | Are any other accelerator pedal position (APP) sensor DTCs set? | -- |
