Powertrain, generic · Transmission
P071E Transmission Mode Switch B Circuit Low
Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo
A transmission mode switch selects an alternative shift schedule such as sport, winter or tow/haul; J2012 does not define which button is A or B. No manufacturer document available to us uses P071A–P071F: GM monitors its analog drive mode switch under its own codes (low below 21–29 % of 5 V, high from 94 %, 200 of 250 samples, two trips), which shows how such buttons are read as coded voltages. P071E means the signal of mode switch B is below its lower limit – a short to ground or a button stuck against ground. Mode B may then be unavailable or permanently active. The opposite is P071F.
Likely causes
Signal wire shorted to ground
Button stuck pressed (switching to ground)
Moisture or dirt in the button
Control module faulty
Symptoms
- Mode B cannot be selected or stays active
- Mode indicator missing or flashing
- Transmission stays on the normal shift schedule
Repair estimate
DifficultyEasyDIY possible
Parts and labour€30–300
Time0.3–1.5 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
transmission mode switchswitch wiringtransmission control module
Related codes
References: law.cornell.edu, gsi.ext.gm.com.