BMW DTC P0977 – Shift Solenoid ‘B’ Control Circuit High
DTC P0977 meaning on BMW
DTC P0977 indicates a fault with the Shift Solenoid ‘B’ Control Circuit in a BMW vehicle. This fault code is triggered when the Engine Control Module (ECM) detects a high voltage condition in the circuit controlling the Shift Solenoid ‘B’.
BMW DTC P0977 symptoms
Symptoms of DTC P0977 in a BMW may include harsh shifting, delayed shifting, transmission slipping, decreased fuel efficiency, and in some cases, the transmission may go into a limp mode where it operates in a single gear.
BMW DTC P0977 causes
The common causes of DTC P0977 in a BMW include a faulty Shift Solenoid ‘B’, damaged wiring or connectors in the control circuit, low transmission fluid level, or a malfunctioning ECM.
BMW DTC P0977 seriousness
Ignoring DTC P0977 in a BMW can lead to further damage to the transmission system, potentially resulting in costly repairs. It is important to address this issue promptly to prevent any long-term damage.
How to diagnose DTC P0977 on BMW
To diagnose DTC P0977 on a BMW, a mechanic would typically start by using a scan tool to retrieve the fault code and then perform a visual inspection of the Shift Solenoid ‘B’ and its wiring. They may also conduct tests to check the solenoid’s resistance and functionality, as well as inspect the transmission fluid level and condition.
How to fix DTC P0977 on BMW
Fixing DTC P0977 on a BMW usually involves replacing the faulty Shift Solenoid ‘B’ and repairing any damaged wiring or connectors in the control circuit. Additionally, ensuring the transmission fluid is at the correct level and in good condition is essential. In some cases, reprogramming or replacing the ECM may be necessary.
How to erase DTC P0977 on BMW
After fixing the underlying issue causing DTC P0977 on a BMW, the fault code can be erased using a scan tool. This will clear the code from the ECM’s memory and reset the transmission system. It is important to verify that the issue has been resolved before clearing the fault code.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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