The P0B38: Motor Electronics Coolant Pump “B” Control Circuit/Open code indicates that there is an open circuit or control issue related to the coolant pump “B” control circuit. This can be caused by faulty wiring, a damaged connector, or a malfunctioning control module. If left unresolved, this can lead to improper cooling of motor electronics, affecting vehicle performance.
P0B38 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0B38: Motor Electronics Coolant Pump “B” Control Circuit/Open |
| Is it serious? | Yes, if the motor electronics are not cooled properly, it can lead to overheating and affect vehicle performance. |
| Possible causes | – Open circuit in coolant pump B control circuit – Faulty wiring or connector – Malfunctioning control module |
| How to diagnose? | – Check for open circuits in the coolant pump B control circuit – Inspect wiring and connectors for damage – Test control module functionality |
P0B38 Meaning
The P0B38 code is triggered when there is an open circuit or control problem in the motor electronics coolant pump “B” control circuit. This may be due to a wiring issue, a faulty connector, or a malfunctioning control module. If not addressed, the lack of proper coolant flow can cause the motor electronics to overheat, potentially leading to damage.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional codes that may provide more context related to the cooling system or electronics. | OBD-II Scanner |
| Check for Open Circuits in the Coolant Pump B Control Circuit | Use a multimeter to check for continuity in the coolant pump B control circuit. An open circuit could indicate a wiring issue or damaged component. | Multimeter |
| Inspect Wiring and Connectors for Damage | Visually inspect the wiring and connectors for signs of corrosion, damage, or loose connections in the coolant pump B control circuit. | Flashlight, Multimeter, Safety Gloves |
| Test Control Module Functionality | Use a diagnostic tool to check the control module’s functionality. If the module is not sending or receiving proper signals, it may need to be replaced or reprogrammed. | Diagnostic Tool |
| Clear the Code and Test Drive | After repairs, clear the code and take the vehicle for a test drive to ensure that 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 P0B38 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.
Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)