How severe is this DTC?
Conditions that contribute to the storage of a P215B code can lead to incorrect speedometer calibration and erratic transmission shifting 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 P215B diagnostic code may include:
- Erratic speedometer
- Inadvertent activation of ABS or traction control system (TCS)
- Irregular transmission shifting patterns
- ABS codes may be stored
- ABS may be disabled
What are some common causes of the code?
Causes
of this P215B code may include:
- Incorrect final drive ratio (differential ring and pinion)
- Excessive metal debris on the vehicle speed sensor output shaft magnet
- Faulty vehicle speed sensor (output)/output shaft
- Transmission slipping
- Cut or damaged wiring or connectors
- Broken, damaged, or worn reluctor ring teeth
- PCM programming error or faulty PCM
What are the diagnostic and troubleshooting steps for P215B?
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 P215B code.
With a stored P215B, I would ensure my automatic transmission is full of clean fluid that doesn’t smell burnt. If the transmission was leaking, I would repair the leak and refill it with fluid, then drive it to ensure it hasn’t suffered mechanical failure.
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 can be helpful as the diagnostic process unfolds. After that, I clear the codes and test drive the vehicle to see if the code resets.
The simplest and most effective method for testing the powered vehicle speed sensor (output) and output shaft speed sensor data is with an oscilloscope. If you have access to an oscilloscope:
- 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 typically 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, operate the drivetrain while observing the waveform on the oscilloscope screen
- You’re 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 vehicle speed sensor (output) and output shaft speed sensor:
- 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’s test specifications
- Sensors not meeting specifications should be considered faulty
Test the vehicle speed sensor (output) and output shaft 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 match the specifications provided in your vehicle information resource (typically 5 volts)
Test the vehicle speed sensor (output) and output shaft 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 the drive wheels securely on the ground, operate 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 vehicle speed sensor (output) and output shaft speed sensor signal circuits at the PCM connector:
Use the DVOM’s positive test lead to probe the appropriate signal circuit at the PCM
The negative test lead should again be grounded
If there is an acceptable sensor signal at the sensor connector that isn’t at the PCM connector, you have an open circuit between the PCM and the sensor being tested