How severe is this DTC?
Conditions that contribute to the storage of a P215A code can lead to ABS deactivation or erratic transmission shift patterns. The code should be considered severe and addressed as soon as possible.
What are some of the symptoms of the code?
Symptoms of a P215A diagnostic code may include:
Erratic speedometer
Inadvertent activation of ABS or traction control system (TCS)
Irregular transmission shift patterns
ABS codes may be stored
ABS may be disabled
What are some common causes of the code?
Causes
of this P215A code may include:
Excessive metal debris on the output speed sensor/wheel magnet
Faulty wheel speed sensor/vehicle speed sensor
Cut or damaged wiring or connectors
Broken, damaged, or worn reluctor ring teeth
Faulty PCM, ABCM, or EBCM
What are the diagnostic and troubleshooting steps for P215A?
A diagnostic scanner with a built-in oscilloscope, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source will be needed to diagnose a P215A code.
You will need the vehicle information resource for wiring diagrams, connector face views, connector pinout diagrams, diagnostic flowcharts, and component testing procedures/specifications. Without this information, successful diagnosis is impossible.
After performing a visual inspection of the wiring and connectors related to the system, I would proceed by connecting the scanner to the vehicle’s diagnostic port and retrieving all stored codes and freeze frame data. I like to note this information as it may be useful as the diagnostic process unfolds. After that, I clear the codes and test the vehicle to see if the code resets.
If you have access to an oscilloscope type:
The following procedure applies to the output speed sensor and all individual wheel speed sensors.
- Connect the oscilloscope’s positive test lead to the signal circuit of the sensor being tested
- Select the appropriate voltage setting on the oscilloscope (sensor reference is usually 5 volts)
- Connect the negative test lead to a ground (sensor ground or battery ground)
- With the drive wheels off the ground and the vehicle secured, run the drivetrain while observing the waveform on the oscilloscope screen
- You are looking for a uniform waveform pattern without voltage spikes or glitches when smoothly accelerating/decelerating through all gears
- If inconsistencies are found, suspect a faulty sensor or poor electrical connection
Test the output speed sensor and individual wheel speed sensors:
- Set the DVOM to the ohms setting and unplug the sensor being tested
- Use the test leads to probe the connector pins and compare your results with the sensor test specifications
- Sensors not meeting specifications should be considered faulty
Test output speed and individual wheel speed sensor reference voltage:
- With key on/engine off (KOEO) and the tested sensor disconnected, probe the sensor connector’s reference circuit pin with the DVOM’s positive test lead
- Simultaneously, the DVOM’s negative test lead should be used to probe the ground pin of the same connector
- The reference voltage should meet the specifications provided in your vehicle information resource (usually 5 volts)
Test output speed sensor and individual wheel speed sensor signal voltage:
- Reconnect the sensor and probe the signal circuit of the sensor being tested with the DVOM’s positive test lead (negative test lead to sensor ground or known good engine ground)
- With key on engine running (KOER) and drive wheels safely on the ground, run the transmission while observing the voltage display on the DVOM
- A speed-voltage chart can be found in the vehicle information source. You can use it to determine if the sensor is functioning correctly at different speeds
- If any of the tested sensors do not reflect the appropriate voltage level (depending on speed), suspect it is faulty.
- If the signal circuit reflects the correct voltage level at the sensor connector, use the DVOM to test the output speed sensor and individual wheel speed sensor signal circuits at their
respective controller connectors:
- Use the DVOM’s positive test lead to probe the appropriate signal circuit at the controller
- The negative test lead should again be grounded
- If there is an acceptable sensor signal at the sensor connector that is not present at the controller connector, you have an open circuit between the controller and the tested sensor.
- Suspect controller failure or programming error only after exhausting all other possibilities.
Use the vehicle information source to gather technical service bulletins (TSBs) that match the vehicle, symptoms, and stored codes in question. A code that applies to your situation can help develop an accurate diagnosis