- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
DTC P2138: Accelerator Pedal Position (APP) Sensor 1-2 Correlation
P2138
• The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.23 volt, 0.25 volt for LLT, with the pedal released.
• The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 0.29 volt, 0.31 volt for LLT, with a partially pressed pedal.
• The ECM detects that the voltage difference between APP sensor 1 and 2 is greater than 1.66 volts, 1.70 volts for LLT, with a fully pressed pedal.
• Any of the above conditions exist, then a 5 second delay for MIL ON.
Diagnostic Aids
Test the current output of the 5-volt reference circuits if you suspect high resistance in the circuit. The current output should be greater than 80 mA for APP 1 and greater than 50 mA for APP 2.
If you don't know how to test the 5 volt reference circuits you need to take it to a qualified repair shop.
Circuit/System Verification
Ignition ON, observe the DTC information with a scan tool. DTC P0651, P0652, P0653, P0697, P0698, or P0699 should not be set.
? If a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699.
Observe the scan tool APP Sensor voltage parameters. Verify both of the APP sensor voltages are between 0.74-4.82 V.
Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. DTCs P2122, P2123, P2127, P2128, or P2138 should not set.
Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs P2122, P2123, P2127, P2128, or P2138 should not set.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Ignition OFF, remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
Disconnect the harness connector at the accelerator pedal assembly.
Test for less than 5 ? between the appropriate low reference circuit of the APP sensor and ground.
? If greater than the specified range, test the low reference circuit of the APP sensor for a short to voltage, or an open/high resistance. If the circuit/connections test normal, replace the ECM.
Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
Note: The 5-volt reference circuit voltage can be within the specified range with a high resistance in the circuit. If this condition is suspected, refer to Diagnostic Aids.
Ignition ON, test for 4.8-5.2 V between the appropriate 5-volt reference circuit of the APP sensor and ground.
? If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM.
? If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
Observe the appropriate scan tool APP sensor voltage parameter. Verify the voltage is less than 0.3 volt.
? If greater than the specified range, test the signal circuit of the applicable APP sensor for a short to voltage. If the circuit/connections test normal, replace the ECM.
Connect a 3 A fused jumper wire between the appropriate signal circuit and the 5-volt reference circuit of the APP sensor. Verify the APP sensor voltage parameter is greater than 4.8 V.
? If less than the specified range, test the appropriate signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
? If both APP sensor voltage parameters display greater than 4.8 V test the signal circuits of the APP sensors for a shorted together condition. If the circuit/connections test normal, replace the ECM.
If all circuits/connections test normal, test or replace the accelerator pedal assembly.
Switching on the aircon will rob the engine of a handful of horses but most people most of the time won't notice. Could be the problem goes deep.
By 2007 most vehicles were digital computer controlled so it isn't easy to guess what is going on. I think you need a guy with a good scanner who knows how to use it who can gather and interpret live data.
Circuit/System Description
The throttle actuator control (TAC) system uses two accelerator pedal position (APP) sensors to monitor the accelerator pedal position. The APP sensors 1 and 2 are located within the pedal assembly. Each sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit.
Two processors are also used to monitor the TAC system data. Both processors are located within the engine control module (ECM). Each signal circuit provides both processors with a signal voltage proportional to pedal movement. The processors share and monitor data to verify that the indicated APP calculation is correct.
DTC P0455: Evaporative Emission (EVAP) System Large Leak
The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED. This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent solenoid valves.
P2138 Throttle/Pedal Pos Sensor Voltage Correlation
Potential Causes of P2138 DTC It's been my experience that the wiring connector or "pig tail" on the throttle body gives problems in the form of a poor connection.The female terminals on the pigtail corrode or pull out of the connector. Possible bare wire on pigtail shorting to ground. The top cover on the throttle body distorted preventing the gears from turning properly. The electronic throttle body is faulty. The accelerator pedal sensor or its wiring failed. The engine management computer has failed. The TPS sensors were not correlating for a few seconds and the computer needs to be cycled through its relearn phase to restore active response to the throttle body, or the computer needs reprogramming at the dealer.
Were the APP codes there BEFORE they replaced the BCM? APP codes usually are an indicator the throttle body needs to be replaced. As a precaution, some recommend to replace the throttle body AND the sensor on the gas pedal together. Unfortunately, this is a dealer only repair most o the time, since the ECM will have to be flashed to sync the new sensors.
×