P273C
Gear Shift Control Module A Supply Voltage Low
The shift-by-wire gear shift control module A reports a supply voltage below the operating range.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Common causes
Ordered by how often each turns out to be the cause.
- Weak battery sags voltage under loadCommon
- Alternator output below regulation pointPossible
Parts involved
- Gear Shift Module A
- Charging System
- Battery
P273C is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.