DTC Advanced Diagnostics: P0793
DTC P0793 : CVT Drive Pulley Speed Sensor Circuit No Signal
General Description
The CVT drive pulley speed sensor is attached to the outside of the transmission housing. The CVT drive pulley speed sensor detects the number of revolutions of the gear on the drive pulley and sends a pulsing signal to the transmission control module (TCM). The TCM converts the pulses to drive pulley speed. If no pulses occur with the drive pulley rotating, the TCM detects a malfunction that may be caused by an open, an intermittent open, or a short to ground. Based on the correlation between the CVT drive pulley speed sensor and the torque converter turbine speed sensor, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 10 seconds or more |
| DTC Type | One drive cycle, MIL on, Shift position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Engine speed [Engine Speed] | 550 rpm | - | |
| Torque converter turbine speed [Torque Converter Turbine Speed] | 350 rpm | - | |
| 12 volt battery voltage [Battery Voltage] | 10.0 V | - | |
| Shift position/mode | D, S | ||
| Other | Not when the shift position is being shifted | ||
| Rotation speed [Secondary Shaft Speed 1 (rpm)] measured by CVT speed sensor is 350 rpm or more | |||
| No electrical noise in the CVT drive pulley speed sensor output circuit | |||
[ ]: HDS Parameter
Malfunction Threshold
The rotation speed [Input Shaft (Drive Pulley) Speed rpm] measured by the CVT drive pulley speed sensor is 60 rpm or less for at least 10 seconds when the rotation speed [Torque Converter Turbine Speed] measured by the torque converter turbine speed sensor is 350 rpm or more.
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 speed sensor NDR-PWM line open (includes a loose or disconnected connector)
- CVT drive pulley speed sensor VCC1 line open (includes a loose or disconnected connector)
- CVT drive pulley speed sensor SG1 line open (includes a loose or disconnected connector)
- CVT drive pulley speed sensor NDR-PWM line short to ground
- CVT drive pulley speed sensor failure
- TCM internal circuit failure
Confirmation Procedure
Operating Condition
- Start the engine.
- Drive the vehicle at a speed of 19 mph (30 km/h) or more for at least 30 seconds.
- 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, the MIL comes on, the shift position indicator blinks, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
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.