DTC Advanced Diagnostics: P1684 (1.5L Engine)
DTC P1684: Throttle Valve Return Spring Performance Problem
General Description
The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the PGM-FI subrelay, the accelerator pedal position (APP) sensor A/B, and the powertrain control module (PCM). The throttle valve return spring is attached to the throttle valve gear to return the throttle valve to the default position. To confirm that the throttle valve is operating normally, and if the detecting condition meets, the throttle valve moves to a specified position and closes to the target position by the throttle valve return spring. If the throttle valve does not move to the target position range, the PCM detects a throttle valve return spring malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 2.5 seconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Engine coolant temperature [ECT Sensor 1] | 157.1 deg.F (69.5 deg.C) | - |
| Vehicle | OFF (LOCK) mode | |
[ ]: HDS Parameter
Malfunction Threshold
The throttle valve opening angle is 17 deg. or more, 11 deg. or less, for at least 2.5 seconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- Throttle valve return spring failure
- Throttle valve friction increase (poor action)
Confirmation Procedure
Operating Condition
- Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on.
- Turn the vehicle to the OFF (LOCK) mode, and wait 10 seconds.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.