P0840
P0840: Transmission Control Module (TCM) Range/Performance Problem
📖 What Does P0840 Mean?
Symptoms
- • Transmission slips
- • hesitates
- • or refuses to engage gears
- • unusual noises
- • or vibrations while driving
Common Causes
- • Faulty transmission solenoid
- • faulty transmission pressure sensor
- • faulty TCM
- • clogged transmission filter
- • low transmission fluid level
Possible Solutions
1. Check transmission fluid level and condition, 2. Scan for any other trouble codes, 3. Test transmission solenoids and pressure sensor, 4. Replace faulty components, 5. Update TCM software if necessary
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❓ Common Questions About P0840
Can I drive with code P0840?
You can drive for a short time, but should address code P0840 soon to avoid worsening the problem or failing an emissions test.
How much does it cost to fix P0840?
The estimated repair cost for code P0840 is between $200 and $1000. This includes parts and labor for most makes and models.
Is this code easy to fix myself?
This repair is considered moderate. It may require specialized tools or significant disassembly. Professional help is recommended if you aren't an experienced DIYer.
Required Parts
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View Best Sellers ↗Related Diagnostic Codes
Other codes that may appear with P0840
P0838: Transmission Control Module (TCM) Range/Performance Problem
P0839: Transmission Control Module (TCM) Range/Performance Problem
P0841: Transmission Control Module (TCM) Range/Performance Problem
P0842: Transmission Control Module (TCM) Range/Performance Problem
💡 Why These Codes Are Related:
- • Similar Issues: Same root cause or component failure
- • Related Problems: Often occur together due to system interactions
- • Sequential Codes: Progressive failure stages or multiple sensors
- • Same System: Components within the same automotive system