BMW DTC P0979 – Shift Solenoid ‘C’ Control Circuit Low
DTC P0979 meaning on BMW
DTC P0979 indicates a low voltage condition in the control circuit of shift solenoid ‘C’ in a BMW vehicle. The Powertrain Control Module (PCM) monitors the voltage levels in the circuit and triggers this diagnostic trouble code when it detects that the voltage is below the specified threshold.
BMW DTC P0979 symptoms
Symptoms of DTC P0979 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 only.
BMW DTC P0979 causes
The common causes of DTC P0979 in a BMW include a faulty shift solenoid ‘C’, damaged wiring or connectors in the control circuit, low transmission fluid level, or a malfunctioning PCM.
BMW DTC P0979 seriousness
Ignoring DTC P0979 in a BMW can lead to further damage to the transmission system and potentially result in costly repairs. It is important to address this issue promptly to prevent any long-term damage to the vehicle.
How to diagnose DTC P0979 on BMW
To diagnose DTC P0979 on a BMW, a mechanic would typically start by using a scan tool to retrieve the fault codes from the PCM. They would then inspect the shift solenoid ‘C’, check the wiring and connectors for any damage, and ensure that the transmission fluid level is adequate. Further testing may involve checking the voltage levels in the control circuit to pinpoint the exact cause of the issue.
How to fix DTC P0979 on BMW
Fixing DTC P0979 on a BMW usually involves replacing the faulty shift solenoid ‘C’, repairing any damaged wiring or connectors in the control circuit, topping up the transmission fluid if necessary, and clearing the fault codes from the PCM. It is recommended to follow the manufacturer’s diagnostic and repair procedures to ensure a proper fix.
How to erase DTC P0979 on BMW
To erase DTC P0979 on a BMW, a mechanic can use a scan tool to clear the fault codes stored in the PCM. After the repair has been completed and the underlying issue has been addressed, clearing the fault codes will reset the system and turn off the Check Engine Light.
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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