Code result
P27A1
Electric/Auxiliary Transmission Fluid Pump A Stuck On
High severity
What it means
The first auxiliary transmission fluid pump runs even when no command is active.
Is it safe to drive?
No — stop driving
This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly.
Most likely causes
TCM output driver stuck on
highOne of the most commonly reported causes for this code — check this first.
Control wire shorted to a permanent B+ supply
mediumA plausible cause — test and verify before replacing parts.
Carbon or debris buildup preventing free movement
lowLess common, but worth ruling out after the more likely causes.
Related help
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