Lexus NX: Throttle / Pedal Position Sensor "A" Minimum Stop Performance (P2109)
DESCRIPTION
The idle speed is controlled by the Electronic Throttle Control System (ETCS). The ETCS is comprised of a throttle actuator, which operates the throttle valve, and a throttle position sensor, which detects the opening amount of the throttle valve. The ECM controls the throttle actuator to adjust the throttle valve opening amount so that the idle speed is maintained at the target idle speed.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
|---|---|---|---|---|---|
| P2109 | Throttle / Pedal Position Sensor "A" Minimum Stop Performance | The ISC learned value is approximately 3 times larger than normal even though the actual intake air amount during idle is within the normal range (up to 1.5 times the normal amount) (5 trip detection logic). | Throttle body with motor assembly | Does not come on | DTC stored |
HINT:
- The ISC learned value is the calculated intake air amount corresponding to the throttle opening amount necessary to maintain the idling speed.
- This malfunction is only detected once per trip. After it has been detected once, the system will not monitor for the malfunction for the rest of the trip.
- The system uses the throttle body with motor assembly and mass air flow meter sub-assembly to detect this malfunction.
MONITOR DESCRIPTION
If there are deposits in the throttle valve, a decrease in the ISC flow rate may cause engine stall or unstable idling. Therefore, the necessary ISC flow rate for idling is maintained using the ISC learned value and feedback. The ECM stores this DTC if the ISC learned value approaches its limit. The ECM begins monitoring for the DTC detection conditions when the following preconditions are met:
1) The mass air flow meter sub-assembly is normal.
2) Atmospheric pressure is 85 kPa(abs) [637.6 mmHg(abs)] or higher.
3) The vehicle has been driven at a speed of 30 km/h (18.7 mph) or more at least once.
4) The engine coolant temperature is 45°C (113°F) or less at engine start, the engine is warmed up and conditions for ISC learning are met, or the power switch has been turned on (IG) (including when the engine is running) for 1 hour or more, the engine is warmed up and conditions for ISC learning are met.
CAUTION / NOTICE / HINT
HINT:
- Read freeze frame data using the Techstream. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
- Since a pending DTC is not stored for this DTC, it takes time to confirm whether the malfunction has been successfully repaired by checking for this DTC. When confirming whether the malfunction has been successfully repaired, compare "ISC Learning Value" recorded in the freeze frame data with "ISC Learning Value" in the Data List after repairs have been made to save time.
PROCEDURE
| 1. | CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2109) |
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs.
Powertrain > Engine and ECT > Trouble Codes| Result | Proceed to |
|---|---|
| DTC P2109 is output | A |
| DTC P2109 and other DTCs are output | B |
HINT:
If any DTCs other than P2109 are output, troubleshoot those DTCs first.
| B | .gif) | GO TO DTC CHART |
|
.gif)
| 2. | READ FREEZE FRAME DATA |
(a) Using the Techstream, check "ISC Learning Value" in the freeze frame data.
Click here .gif)
HINT:
Be sure to confirm "ISC Learning Value" in the freeze frame data as it is used when confirming whether the malfunction has been successfully repaired.
|
| 3. | REMOVE FOREIGN OBJECT (CLEAN THROTTLE BODY WITH MOTOR ASSEMBLY) |
| *1 | Bore |
| *2 | Valve |
| *a | Reference |
| *b | Throttle Body with Motor Assembly Cross-section Diagram |
| *c | When valve fully opened |
| *d | Deposits |
| *e | Do not directly apply cleaner |
(a) Clean off any deposits from the inside of the throttle body with motor assembly.
(1) Push open the throttle valve and wipe off any carbon from the valve and bore using a piece of cloth soaked in non-residue solvent.
NOTICE:
- Make sure that the cloth or your fingers do not get caught in the valve.
- Make sure that foreign matter does not enter the throttle valve.
- Do not directly apply non-residue solvent to the throttle body with motor assembly or wash the throttle body with motor assembly. Cleaning solvent may leak into the motor from the shaft and cause problems such as rust or valve movement problems.
- If there is coating material on the edge of the valve, be careful not to remove it.
- Push the throttle valve open gently with your finger and check that the throttle valve moves smoothly.
HINT:
- If the throttle valve does not move smoothly, replace the throttle body with motor assembly.
- The illustration are for reference only. Actual parts may differ.
|
| 4. | READ VALUE USING TECHSTREAM (ISC LEARNING VALUE) |
(a) Perform "Inspection After Repair" after cleaning the throttle body with motor assembly.
Click here
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(d) Turn the Techstream on.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / ISC Learning Value.
Powertrain > Engine and ECT > Data List| Tester Display |
|---|
| ISC Learning Value |
(f) Read the value.
OK:
The value is half of "ISC Learning Value" recorded in the freeze frame data or less.
HINT:
Perform "Inspection After Repair" after replacing the throttle body with motor assembly.
Click here
| OK | | END |
| NG | | REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY |
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