P071A code meaning
Transmission Mode Switch A Circuit
What P071A means
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. P071A is the general circuit fault of mode switch A: its state is invalid or implausible. The transmission then usually stays on its normal schedule. Low and high are P071B/P071C, switch B has P071D–P071F; the range sensor (PRNDL) is P0705 ff.
P071A at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P071A
- Mode A cannot be selected or stays active
- Mode indicator missing or flashing
- Transmission stays on the normal shift schedule
Common causes of P071A
- Most likelyMode switch A faulty (selector lever or console)
- PossibleWiring or connector in the console damaged (spilled drinks, chafing)
- Less likelyResistor coding drifted (analog buttons)
- Less likelyControl module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Transmission mode switchSwitch wiringTransmission control module
What each part of P071A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| 1A | The exact fault in that area. |
What to do next
- Note P071A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P071A
What does P071A mean?
P071A means "Transmission Mode Switch A Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P071A?
P071A does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P071A fail an emissions test?
P071A is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P071A to fix?
Difficulty: easy. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P071A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.