DTC Advanced Diagnostics: P1898
DTC P1898 : CVT Drive Pulley Pressure Control Solenoid Valve Stuck ON or CVT Driven Pulley Pressure Control Solenoid Valve Stuck OFF
General Description
The CVT drive pulley pressure control solenoid valve and the CVT driven pulley pressure control solenoid valve control hydraulic pressure. The CVT drive pulley pressure control solenoid valve and the CVT driven pulley pressure control solenoid valve are controlled by duty cycle output. The spool in the CVT drive pulley pressure control solenoid valve and the CVT driven pulley pressure control solenoid valve moves the valve according to the current, and produces hydraulic pressure in proportion to the current. The transmission control module (TCM) measures the current that passes through the CVT drive pulley pressure control solenoid valve and the CVT driven pulley pressure control solenoid valve and uses feedback control to compensate for the difference between the measured current and the commanded one. To shift the transmission properly, the TCM outputs a drive/driven pulley hydraulic pressure control signal. If the pulley ratio is out of specified range from the vehicle stopped with the forward clutch engaged to the vehicle running, the TCM detects a CVT drive pulley pressure control solenoid valve stuck ON failure or a CVT driven pulley pressure control solenoid valve stuck OFF and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | Depending on the driving conditions |
| DTC Type | Two drive cycles, MIL on, Shift position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Engine speed [Engine Speed] | 500 rpm | - | |
| Vehicle speed [Vehicle Speed] | - | 3 mph (5 km/h)* | |
| 9 mph (13 km/h) ** | - | ||
| Accelerator pedal position | 2.7 deg. | - | |
| Shift position/mode | D | ||
* : Symptom 1
**: Symptom 2
[ ]: HDS Parameter
Malfunction Threshold
One of these symptoms occurs.
| Symptom | Vehicle conditions | TCM detection | |
|---|---|---|---|
| 1 | Stopped with forward clutch engaged | Pulley ratio [Pulley Ratio] is more than 2, or less than 3 for at least 400 milliseconds | |
| 2 | Running | Pulley ratio [Pulley Ratio] is more than 1.8, or less than 3 | |
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.
- CVT drive pulley pressure control solenoid valve stuck on
- CVT driven pulley pressure control solenoid valve stuck off
Confirmation Procedure
Operating Condition
- Start the engine.
- Accelerate the vehicle in D position/mode until the speed reaches 37 mph (60 km/h).
- Slow down and stop the vehicle.
- Accelerate the vehicle with wide open throttle.
- Slow down and stop the vehicle.
- Turn the vehicle to the OFF (LOCK) mode.
- Repeat Driving Pattern steps 1 through 5.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.
Conditions for clearing the DTC
The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. 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, and the freeze data can be cleared with the scan tool clear command.