What Does P071E Mean?
The transmission mode switch B circuit is reporting a low voltage condition. The signal is either shorted to ground, the switch is stuck in a low-output position, or a wiring fault is pulling the signal below the expected threshold. The TCM cannot properly read the driver's mode selection from the B switch input.
Common Causes
35%
Mode switch B shorted internally or stuck producing low output
25%
Signal wire shorted to ground in the harness
20%
Corroded connector creating an unintended ground path
10%
Liquid or debris contamination in the switch assembly
10%
TCM input circuit issue pulling the signal low
Diagnostic Steps
1
Monitor the mode switch B voltage PID. If it reads near 0V in all switch positions, the circuit has a ground-level fault.
2
Disconnect the mode switch B connector. If the voltage rises to the reference level, the switch is shorted. If it remains low, the harness has a short to ground.
3
Inspect the switch assembly and connector for contamination, corrosion, or physical damage from spills or wear.
4
Check resistance from the signal wire to ground at the switch connector (disconnected). Should read open (OL). A low reading pinpoints a harness short.
5
If the switch and harness are OK, check the TCM connector pin for the B switch input. Verify no internal or adjacent-pin short.
Estimated Repair Cost
$50 - $300
Parts + labor, varies by vehicle and location
The transmission mode switch B circuit is reporting a low voltage condition. The signal is either shorted to ground, the switch is stuck in a low-output position, or a wiring fault is pulling the signal below the expected threshold. The TCM cannot properly read the driver's mode selection from the B...
The most common cause of P071E (Transmission Mode Switch "B" Circuit Low) is: Mode switch B shorted internally or stuck producing low output
Typical repair costs for P071E range from $50 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. Normal transmission operation is maintained in default mode. The mode switch B functionality is simply unavailable. This is a convenience issue only.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P071E to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission
Difficulty
Type
Generic (SAE)
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