Error Code P07B8 is defined as Transmission Park Position Sensor/Switch B Circuit Open, meaning it applies to all cars with the OBD-II system, especially those made from 1996 onwards and equipped with automatic transmission. Specifications on the definition and steps for repairs may vary depending on the model and make of your 2017 Volvo S90 .
This includes cars from, but not limited to, Chevrolet, Dodge, Ford, Land Rover, Toyota, and Volkswagen. Specifications on the definition, troubleshooting, and repairs, of course, vary between make, model, and powertrain configuration.
This code indicates that the PCM (control module, also known as ECM or engine control module in other 2017 Volvo S90 makes) has detected a malfunction that affects the operation of the transmission park position sensor/switch “B”.
The job of the transmission park position sensor/switch “B” is to observe the status of the transmission. When the transmission is placed in park position, the circuit sends signals to the PCM. Based on the specific 2017 Volvo S90 , this is a safety feature to keep the starter from engaging with the automatic transmission in gear.
With that said, it is associated with several Transmission Park Position Sensor/Switch “A” Circuit codes, namely:
The specific situation determines the code that the PCM activates. When the Error Code P07B8 appears, that means that there is an open circuit detected in the transmission park position sensor/switch “B” circuit.
As with most error code problems, the first step to troubleshoot this code is to check with the Technical Service Bulletin (TSB) for the common issues with your 2017 Volvo S90 .
Next, find all the components associated with the transmission park position sensor/switch “A” circuit. This includes the transmission park sensor/switch itself, connectors, wiring, and PCM. Depending on the make, model, and year of your 2017 Volvo S90 , the components may come with more components. Check all these components thoroughly. Make sure there are no visible problems with the wires (bare, burn, scraped, etc.). Also, make sure you check the connectors. Look for signs of corrosion buildup or damaged pins.
This is usually 2017 Volvo S90 specific and may require special tools and equipment to perform, such as digital multimeter and your 2017 Volvo S90 ’s specific technical references. Also, voltage requirements may vary based on the make, model, and specific year of your 2017 Volvo S90 .
As said earlier, voltage requirements can vary on the specific 2017 Volvo S90 , as well as the transmission park position sensor/switch circuit configuration and other components. Thus, you should check it with the technical data. Find the right voltage specifications and follow the specific troubleshooting sequence. Internal failure usually happens when the right voltage input to a sensor/switch without the voltage output.
If the troubleshooting showed the absence of a power source or ground, then conduct a continuity test to check the condition of the connectors and wirings. A continuity test is performed with the power removed from the circuit. The normal reading must be at 0 ohms of resistance unless otherwise specified in the technical data.
Resistance or no continuity means there is a problem with the connectors or wirings, or there is an open or short in the wiring. Replace or repair as necessary.
Common repairs for this code include:
The severity of this error code usually depends on the specific malfunction and the level of progress. However, this problem could become a safety issue, since the starter will engage with your 2017 Volvo S90 in gear. Thus, to prevent its progress, it is vital to address it as soon as possible.