Transmission Control Module (TCM) Power Supply Voltage Too Low
The TCM has detected a voltage supply issue.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The Transmission Control Module is not getting enough voltage to function properly—this means it can't control the transmission like it should.
What the computer is actually seeing
The TCM expects to see a voltage between 10 and 16 volts while the engine is running. If the voltage drops below 10 volts, it triggers this code.
What a healthy reading looks like
Voltage input should be between 10-16 volts.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check battery voltage with the engine running. It should be between 13.5V and 14.5V. If it's low, charge or replace the battery. Decision: If the voltage is normal, go to step 2.
- 22. Inspect wiring and connectors going to the TCM for damage or corrosion. Use a multimeter to check for continuity. Decision: If wiring is damaged, repair or replace it. If wiring is okay, go to step 3.
- 33. Check the ground connection for the TCM to ensure it's clean and tight. Voltage drop tests may help identify issues. Decision: If ground is good, go to step 4.
- 44. If all checks are good, consider replacing the TCM as it may be faulty.
Common causes
- Low battery voltage
- Faulty wiring or connectors to the TCM
- Defective TCM
- Corroded ground connections
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may impact shifting, so avoid aggressive driving and get it fixed soon.
Will this code return after repairs?
If the underlying issue is fixed correctly, it should not return.
Why does this code appear with low battery voltage?
Low voltage can cause the TCM to malfunction, leading to this code.
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