What Does P2840 Mean?
The TCM has detected a fault in the shift fork D position sensor circuit. This indicates a complete circuit failure preventing proper monitoring of shift fork D position in the transmission.
Common Causes
35%
Failed shift fork D position sensor
30%
Open or shorted wiring in shift fork D position sensor circuit
20%
Damaged or corroded connector at shift fork D position sensor
10%
TCM internal failure or communication fault
5%
Mechanical damage to shift fork D or sensor alignment issue
Diagnostic Steps
1
Step 1: Inspect shift fork D position sensor connector for corrosion, damage, moisture, or loose fit; clean and secure
2
Step 2: Check power supply and ground at shift fork D position sensor connector with multimeter
3
Step 3: Test shift fork D position sensor operation and resistance values per manufacturer specifications
4
Step 4: Check wiring harness continuity between sensor and TCM; test for shorts to ground or power
5
Step 5: Replace shift fork D position sensor if all circuits test normal; perform TCM relearn procedure
Estimated Repair Cost
$400 - $1,500
Parts + labor, varies by vehicle and location
The TCM has detected a fault in the shift fork D position sensor circuit. This indicates a complete circuit failure preventing proper monitoring of shift fork D position in the transmission.
The most common cause of P2840 (Shift Fork "D" Position Circuit) is: Failed shift fork D position sensor
Typical repair costs for P2840 range from $400 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transmission may default to limp mode with restricted gear availability. Vehicle can typically be driven cautiously but should be repaired soon to prevent potential internal transmission damage from incorrect shift fork operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2840 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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