Code Severity and Symptoms
Since conditions that can lead to storing a P2160 code may create driving and ABS issues, it should be classified as severe and addressed as quickly as possible.
Symptoms of a P2160 code may include:
- Erratic speedometer/odometer operation
- Irregular transmission shifting patterns
- Illumination of check engine light soon, traction control light, or anti-lock brake light
- Unexpected activation/deactivation of traction control system (if equipped)
- Other transmission and ABS codes may be stored
- ABS system may be rendered inoperative in some cases
Causes
Possible causes of this code include:
- Excessive metallic debris buildup on speed sensors
- Faulty wheel speed sensor or vehicle speed sensor
- Cut or damaged wiring harnesses or connectors (particularly near speed sensors)
- Damaged or worn teeth on a reluctor ring
- Faulty PCM, ABCM, or EBCM
Diagnostic and Repair Procedures
A diagnostic scanner, digital volt/ohmmeter (DVOM), possibly an oscilloscope, and a reliable source of vehicle information will be needed when diagnosing a P2160 code.
I normally like to begin my diagnosis of a P2160 with a visual inspection of the system wiring, speed sensors, and connectors. Repair open or shorted circuits as needed and clean excessive metallic debris from affected sensors. Check reluctor ring integrity during sensor inspection.
Connect the scanner to the vehicle’s diagnostic port and retrieve all stored trouble codes and available freeze frame data. Before clearing codes, note this information as it may prove useful as your diagnosis progresses.
Using your vehicle information source, research applicable Technical Service Bulletins (TSBs). If you find a TSB that matches the symptoms and stored codes of the vehicle in question, the diagnostic information it contains will likely help diagnose the P2160 from here.
Use the scanner’s data stream to observe wheel speeds and vehicle speed during vehicle road testing. You can narrow the data stream to display only relevant fields to increase the speed and accuracy of desired data delivery. Inconsistent or erratic readings from VSS or wheel speed sensors may lead you to wiring, electrical connector, or sensor issues by narrowing the general area of system malfunction.
After locating the VSS circuit from which the low voltage input is initiated, use the DVOM to perform a resistance test on the sensor in question. Consult your vehicle information source for manufacturer recommendations regarding VSS testing and replace sensors that don’t meet specifications.
Use the oscilloscope to retrieve live data from each individual VSS by probing the sensor signal wire and sensor ground wire. Lifting or jacking up the vehicle will almost always be necessary to properly perform this type of test. Once the drive axle(s) are securely fixed to the ground, rotate the transmission while observing the waveform on the oscilloscope. Focus on glitches or inconsistencies in the pattern and proceed with diagnosis accordingly.
Vehicle speed sensors can be damaged during routine maintenance, while wheel speed sensors and sensor wiring harnesses are frequently damaged during brake repair. If this code is presented immediately after a repair, suspect a damaged sensor harness, connector, or sensor.
Additional Diagnostic Notes:
- When performing circuit resistance and continuity tests with a DVOM, always disconnect electrical connectors from associated controllers – failure to do so could result in damaged controller
Exercise caution when removing sensors from transmission housings as hot transmission fluid may be inadvertently released