P2122
P2122 Acceleration Position Sensor 1 Circuit Low Input
Component Location
General Description
The ETS (Electronic Throttle System) is the throttle body whose throttle angle is controlled by control module. It consists of ETS unit, ETS-motor, Accelerator Position Sensor (APS), Throttle Position Sensor (TPS) and Limp home valve. Among above-mentioned parts , APS consists of APS1, APS2 and idle switch which detects the closed throttle position. When a driver steps on the gas pedal, the output signal of APS1 is sent to ETS unit and that of APS2 is sent to the PCM. And then the PCM sends throttle valve target opening value to ETS unit after calculating from signals such as APS and other input values. The ETS unit controls ETS motor to meet PCM�s throttle valve target opening value.
DTC Description
This DTC is set if the signal voltage of acceleration position sensor 1 is lower than threshold value.
DTC Detecting Condition
Specification
Schematic Diagram
Signal Waveform
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
1) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Power Circuit Inspection" procedure.
Power Supply Circuit Inspection
Check Power to Acceleration Position Sensor 1 (APS1)
1. Ignition "OFF".
2. Disconnect APS connector.
3. Ignition "ON" & Engine "OFF".
4. Measure voltage between terminal "8" of APS harness connector and chassis ground.
A. Specification: approx. 5V
5. Is the voltage within specifications?
YES
1) Go to "Signal Circuit Inspection" procedure.
NO
1) Check for open or short to chassis ground in harness, Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Signal Circuit Inspection
Check for Open in Harness
1. Ignition "OFF".
2. Disconnect APS connector and ETS unit connector.
3. Measure resistance between terminal "6" of APS harness connector and "20" of ETS unit harness connector.
A. Specification: Approx. 0 ohm
4. Is the resistance within specifications?
YES
1) Go to "Check for Short to Ground in Harness" as below.
NO
1) Check for open in signal harness, Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Check for Short to Ground in Harness
1. Ignition "OFF".
2. Disconnect APS connector and ETS unit connector.
3. Measure resistance between termianl "7" of APS harness connector and chassis ground.
A. Specification: infinite
4. Does the resistance indicate open?
YES
1) Go to "Component Inspection" procedure.
NO
1) Check for short to chassis ground in control harness, Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
Component Inspection
Check APS
1. Ignition "OFF".
2. Disconnect APS connector.
3. Measure resistance between terminal "7" and "8" of APS connector.
A. Specification: Approx. 3.5 ~ 6.5k ohms at 20°C(68°F)
4. Monitor the signal output of APS1 during stepping on the accelerator pedal slowly.
A. Specification
1) Approx. 0.3 ~ 1.0V (when not stepping on the accelerator pedal)
2) Approx. 4.0 ~ 5.5V (when stepping on the accelerator pedal fully)
5. Is the resistance or the signal voltage within specifications?
YES
1) Substitute with a known-good ETS unit or PCM and check for proper operation. If the problem is corrected,replace ETS unit or PCM and then go to "Verification of Vehicle Repair" procedure.
If the ETS unit needs to be replaced, do initialization after it is replaced.
NO
1) Check APS for contamination, deterioration, or damage. Substitute with a known-good APS and check for proper operation.If the problem is corrected, replace APS and then go to "Verification of Vehicle Repair" procedure.
- Procedure of Initializtion
1. Erase the trouble codes on PCM
2. Turn the ignition key on less than 1second and turn it off (Do not start the engine).
3. Turn the ignition key off and keep this condition until the main relay is turned off. (It will takes 10 second)
4. Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM.
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear DTC.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTC�s present ?
YES
1) Go to the applicable troubleshooting procedure.
NO
1) System is performing to specification at this time.