DTC Advanced Diagnostics: P0502
DTC P0502 : CVT Speed Sensor Circuit Open/Short
General Description
The CVT speed sensor is attached to the outside of the transmission housing. The CVT speed sensor detects the number of revolutions of the secondary driven gear and sends a pulsing signal to the transmission control module (TCM). The TCM converts the pulsing signal into vehicle speed. If no pulses occur with the secondary driven gear rotating, the TCM detects a malfunction that may be caused by an open, an intermittent open, or a short to ground. If no signal from the CVT speed sensor is received for a set time, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 4 seconds or more |
| DTC Type | One drive cycle, MIL on, Shift position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Engine speed [Engine Speed] | 500 rpm | - | |
| Drive pulley speed [Input Shaft (Drive Pulley) Speed rpm] | 200 rpm | - | |
| 12 volt battery voltage [Battery Voltage] | 10.0 V | - | |
| Shift position/mode | D, S | ||
| Other | No electrical noise in the CVT speed sensor output circuit | ||
| Decelerate and fuel cut-off for at least 3 seconds | |||
[ ]: HDS Parameter
Malfunction Threshold
No signal from the CVT speed sensor is detected for at least 4 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.
- CVT speed sensor VEL-PWM line open (includes a loose or disconnected connector)
- CVT speed sensor VCC3 line open (includes a loose or disconnected connector)
- CVT speed sensor SG3 line open (includes a loose or disconnected connector)
- CVT speed sensor VEL-PWM line short to ground
- CVT speed sensor failure
- TCM internal circuit failure
Confirmation Procedure
Operating Condition
- Start the engine.
- Drive the vehicle at a speed of 37 mph (60 km/h) or more.
- Release the accelerator pedal, and slow the vehicle.
- 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.