The P0B42: Hybrid Battery Voltage Sense “B” Circuit Low code indicates that the voltage reading from the hybrid battery voltage sense “B” circuit is lower than expected. This could be caused by a faulty voltage sensor, an electrical issue, or a wiring problem. If left unresolved, low voltage readings can lead to improper battery management and affect the performance of the hybrid system.
P0B42 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0B42: Hybrid Battery Voltage Sense “B” Circuit Low |
| Is it serious? | Yes, low voltage readings can impact battery monitoring and hybrid system performance. |
| Possible causes | – Low voltage reading from sense B – Faulty sensor – Electrical issue |
| How to diagnose? | – Measure voltage sense B reading – Test sensor functionality – Inspect electrical system |
P0B42 Meaning
The P0B42 code is set when the voltage sense “B” circuit in the hybrid battery detects a voltage lower than the manufacturer’s specifications. This could be due to a malfunctioning sensor, wiring issues, or other electrical problems. Low voltage readings may result in inaccurate battery monitoring, affecting the performance and efficiency of the hybrid system.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional related codes that may provide more context for the issue. | OBD-II Scanner |
| Measure Voltage Sense B Reading | Use a multimeter to measure the voltage in the sense B circuit and compare it to manufacturer specifications. | Multimeter |
| Test Sensor Functionality | Test the voltage sensor in circuit B to ensure it is functioning correctly. Replace the sensor if necessary. | Multimeter, Diagnostic Tool |
| Inspect Electrical System | Inspect the wiring and electrical connections for damage, corrosion, or loose connections that could lead to low voltage readings. | Flashlight, Multimeter, Safety Gloves |
| Clear the Code and Test Drive | After performing repairs, clear the code and take the vehicle for a test drive to ensure the issue is resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | Rescan the vehicle after the test drive to confirm that the P0B42 code does not return. | OBD-II Scanner |
Free PDF: How to choose OBD2 scanner
I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.
