DTC Advanced Diagnostics: P0715
DTC P0715:Input Shaft (Mainshaft) Speed Sensor Circuit Malfunction

General Description

The powertrain control module (PCM) monitors the input (mainshaft) speed sensor for rationality faults. The mainshaft speed is calculated from the PWM signal received from the input (mainshaft) speed sensor. The mainshaft speed is continuously monitored against engine speed in order to detect rationality faults. If the absolute difference between the mainshaft speed and the engine speed is a specified value, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
5 seconds or more
DTC Type
Two drive cycles, MIL off

Enable Conditions
Condition
Minimum
Maximum
Time the clutch pedal is not pressed
5 seconds
–
Vehicle speed [Vehicle Speed]
10 mph (15 km/h)
–
Other
Gear is engaged
[ ]: HDS Parameter

Malfunction Threshold
The absolute difference between the mainshaft speed [M SHAFT SPD] and the engine speed [Engine Speed] is greater than 500 rpm.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Input (mainshaft) speed sensor NM line short to ground
Input (mainshaft) speed sensor NM line open
Input (mainshaft) speed sensor VCC line open
Input (mainshaft) speed sensor SG line open
Input (mainshaft) speed sensor connector disconnection
Input (mainshaft) speed sensor failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
1.
Start the engine. Hold the engine speed [Engine Speed] at 3,000 rpm without load (in neutral) until the radiator fan comes on.
2.
Drive the vehicle at speed over 10 mph (15 km/h) for a while.
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 PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. The MIL does not come on.

Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.