P06A7 Sensor B Reference Circuit Range / Performance

P06A7 Sensor B Reference Circuit Range / Performance

OBD-II DTC Datasheet

Sensor B Reference Circuit Range / Performance

What does this mean?

This Diagnostic Trouble Code (DTC) is a generic transmission code, which means it applies to OBD-II equipped vehicles. This may include, but is not limited to, Ford, Chevrolet, Honda, etc. While general, specific repair steps may vary depending on the brand / model.

If your OBD-II vehicle has a stored code P06A7, it means that the powertrain control module (PCM) has detected an out-of-range reference voltage signal or a problem with the specific sensor labeled “B”. The sensor in question is usually associated with an automatic transmission, transfer case, or one of the differentials.

A more specific sensor code almost always accompanies this code. P06A7 adds that the sensor reference circuit voltage is out of range or expected. To determine the location and function of sensor “B” for the vehicle in question, consult a trusted source of vehicle information (eg AllDataDIY). Suspect there is a PCM programming error if P06A7 is stored separately. You will need to diagnose and repair any other sensor codes before diagnosing and repairing a P06A7, but be aware of the range / performance reference voltage status.

The sensor in question is supplied with a reference voltage (usually 5 V) through a switched (powered when the switch is on) circuit. There will also be a ground signal. The sensor will be either variable resistance or electromagnetic type and it completes the circuit. The resistance of the sensor should decrease with increasing pressure, temperature or speed, and vice versa. As the resistance of the sensor changes (depending on conditions), it supplies the PCM with an input voltage signal.

Example of PKM photo:

If the input voltage signal received by the PCM is outside the expected parameters, P06A7 will be stored. The malfunction indicator lamp (MIL) may also be illuminated. Some vehicles will require several driving cycles (in the event of a failure) for the warning lamp to illuminate. Let the PCM go into readiness mode before assuming a repair is successful. Just remove the code after repair and drive as normal. If the PCM goes into readiness mode, the repair was successful. If the code is cleared, the PCM will not go into standby mode and you know the fault is still there.

Severity and symptoms

The severity of this DTC depends on which sensor circuit is experiencing the abnormal voltage. Other stored codes must be reviewed before a severity determination can be made.

Symptoms of a P06A7 code may include:

• Inability to switch the transmission between sport and economy modes
• Gear shift malfunctions
• Delay (or lack) of turning on the transmission
• Transmission failure to switch between XNUMXWD and XNUMXWD
• Failure of the transfer case to switch from low to high gear
• Lack of inclusion of the front differential
• Lack of engagement of the front hub
• Incorrect or not working speedometer / odometer

reasons

Possible causes of this engine code include:

• Bad sensor
• Defective or blown fuses and / or fuses
• Faulty system power relay
• Open circuit and / or connectors

Diagnostic and repair procedures

Diagnosing a stored P06A7 code will require a diagnostic scanner, a digital volt / ohmmeter (DVOM), and a trusted source of vehicle information (such as All Data DIY). A handheld oscilloscope can also be helpful in making a diagnosis.

First, consult your vehicle information source to determine the location and function of the sensor in question, as it relates to your specific vehicle. Visually inspect the harness and connectors associated with the sensor system. Repair or replace damaged or burnt wiring, connectors, and components as needed. Secondly, connect the scanner to the vehicle diagnostic port and retrieve all stored DTCs and freeze frame data. Make a note of the codes along with the order in which they were stored and any relevant freeze frame data, as this information may be helpful if the code turns out to be intermittent. Now you can go ahead and clean up the code; then test drive the vehicle to make sure it is reset immediately.

If the code resets immediately, use the DVOM to test the reference voltage and ground signals on the sensor in question. Typically you would expect to find 5 volts and ground at the sensor connector.

Continue testing sensor resistance and continuity levels if voltage and ground signals are present at the sensor connector. Obtain test specifications from your vehicle information source and compare your actual results to them. Sensors that do not meet these specifications should be replaced.

Disconnect all related controllers from the system circuits before testing resistance with the DVOM. Failure to do so could damage the PCM. If the reference voltage is low (at the sensor), use the DVOM to test the circuit resistance and continuity between the sensor and the PCM. Replace open or shorted circuits as necessary. If the sensor in question is a reciprocating electromagnetic sensor, use an oscilloscope to track the data in real time. Focus on crashes and completely open circuits.

Additional diagnostic notes:

• This type of code is usually provided as support for more specific code.
• The stored code P06A7 is usually associated with the transmission.

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NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.