P0715 Code (Symptoms, Causes, and How to Fix)
Nothing ruins your day quite like seeing your check engine light suddenly flash on. When this happens, your scan tool (or mechanic) will let you know what fault code(s) you’re dealing with.
One such code that often throws motorists for a loop is P0715. If you’re currently dealing with this fault code yourself, read on, as the following will serve as a comprehensive guide to all things P0715.
- P0715 indicates a transmission input speed sensor malfunction.
- Unless an emergency, do not continue driving.
- Symptoms rough shifting, erratic speedometer, and possible stalling.
- Usually caused by faulty speed sensor or related wiring.
What Does Code P0715 Mean?
Diagnostic fault code P0715 refers to a perceived lack of viable feedback from a transmission’s input speed sensor, as perceived by a vehicle’s PCM. Accurate feedback from this particular sensor is required for the PCM or TCM to determine shift points, and respond properly. This data is assessed jointly, with feedback from a transmission’s output speed sensor.
Without rational or viable feedback from the input speed sensor, many vehicles will default to “limp mode”, in which engine performance will be significantly debated. This safeguard is intended to prevent additional damage from being incurred, under circumstances when shift-point accuracy becomes compromised.
The input speed sensor itself is typically located along the torque converter end of a vehicle’s transmission, within close proximity of the transmission’s input shaft.
Affixed to or driven by this shaft is a tone ring or reluctor wheel, with individual teeth that create magnetic pulses as they pass in front of the probe end of the input speed sensor mounted above. These pulses generate a defined electrical signal that is then relayed to the PCM, by way of the TCM.
In the case of DTC P0715, the pulse-derived signal fielded and delivered by the transmission’s input speed sensor does not correspond to various additional speed inputs as anticipated. Feedback from this sensor is either erratic or non-existent, making the accurate determination of transmission input speed impossible.
Related: P0500 Code, P0720 Code
Symptoms of Code P0715
When you get a P0715 code, you’ll likely notice several other signs something is wrong. Paying attention to these symptoms can help you figure out what’s causing the problem more quickly.
- Illuminated check engine light
- Rough or exaggerated shifts
- Potential stalling at stops
- Erratic speedometer operation
- Initiation of “limp mode”
- Reduced fuel economy
Causes of Code P0715
DTC P0715 can be triggered by several different underlying problems, with some being harder to identify than others. The first step in fixing the issue is understanding what might be causing it in the first place. Here are the most likely causes:
- Faulty input speed sensor
- Inoperable output speed sensor
- Damaged speed sensor circuit wiring
- Compromised reluctor ring/shaft
- Torque converter abnormalities
- PCM hardware issues
Is Code P0715 Serious?
Diagnostic fault code P0715 is generally regarded as being of moderate severity, due primarily to the negative impacts this fault can have on a vehicle’s driveability. You should not drive the vehicle unless in an emergency.
This fault is commonly connected to issues such as unanticipated stalling of a vehicle’s engine and hard or erratically shifting transmissions. A noteworthy reduction in fuel economy and speedometer accuracy is also not unheard of when this fault is active.
Additionally, when overlooked or ignored for prolonged periods of time, underlying issues pertaining to DTC P0715 can actually pose an increased risk of internal transmission issues. Sustained hard or erratic shifts can compromise a transmission’s integrity over time, causing increased shock to vital internal shafts and geartrain components.
In any case, the root cause of diagnostic fault code P0715 should be diagnosed and repaired as soon as possible. Doing so will minimize the risk of incurring additional drivetrain damage, while also alleviating potential driveability-related symptoms of great significance.
If you’re not confident about making these repairs yourself, make an appointment with a trusted mechanic as soon as possible.
How to Fix Code P0715
The following steps can be used to assist in diagnosing and repairing the root cause of DTC P0715. You’d also best advised to consult a factory-specific service manual for your particular model of vehicle before starting any repairs.
#1 – Check For Additional DTCs
Before getting started, check for the presence of any additional diagnostic fault codes with the use of an OBD-II scan tool. Any such faults that are retrieved, should be diagnosed before proceeding, in order of severity.
#2 – Inspect Speed Senor/Wiring
Begin by performing a thorough visual examination of the affected vehicle’s transmission input speed sensor, and all related wiring. Any damage observed should be fully repaired before proceeding. You should also check for corrosion or water contamination within the sensor’s connector.
#3 – Inspect Sensor Face For Metallic Debris
Next, carefully remove the affected sensor from the vehicle’s transmission, before inspecting the probe end of this sensor for contamination with metal debris. Thoroughly wipe away any metal that is present.
#4 – Verify Voltage/Ground Delivery
Continue by verifying that suitable power/ground delivery is present at the input speed sensor itself, while back-probing the correct wires within the sensor plug. These values should be compared to those specified by the vehicle’s manufacturer.
#5 – Test Senor Feedback
Next, you’ll need to verify that all feedback from the vehicle’s input speed sensor falls within range, as dictated by factory-specific service literature.
If this feedback does fall within range, feedback should again be checked on the PCM and/or TCM side of the corresponding electrical harness, to validate feedback circuit continuity. However, if feedback does not fall within range, sensor replacement is suggested.
- 3 Symptoms of a Bad Starter Solenoid (and Replacement Cost) - Dec 3, 2024
- P0715 Code (Symptoms, Causes, and How to Fix) - Nov 25, 2024
- 5 Symptoms of a Bad Oxygen Sensor (and Replacement Cost) - Nov 12, 2024