What Does P2796 Mean?
The transmission control module cannot properly control the auxiliary transmission fluid pump due to an open circuit or electrical fault. This pump supplements the main transmission pump during specific conditions like idle or electric-only operation in hybrids.
Common Causes
35%
Failed auxiliary transmission fluid pump motor or seized pump
25%
Open circuit or broken wire in pump control circuit
20%
Blown fuse or faulty relay for auxiliary pump power
15%
Corroded or damaged connector at pump or TCM
5%
Faulty transmission control module output driver
Diagnostic Steps
1
Step 1: Check auxiliary pump fuse and relay operation using multimeter and test light
2
Step 2: Test for battery voltage at pump connector with key on or pump activated
3
Step 3: Measure pump motor resistance and compare to specifications (typically 1-5 ohms)
4
Step 4: Command pump operation with scan tool and listen/feel for pump activation
5
Step 5: Test ground circuit continuity and check for excessive resistance in power supply circuit
Estimated Repair Cost
$300 - $1,500
Parts + labor, varies by vehicle and location
The transmission control module cannot properly control the auxiliary transmission fluid pump due to an open circuit or electrical fault. This pump supplements the main transmission pump during specific conditions like idle or electric-only operation in hybrids.
The most common cause of P2796 (Auxiliary Transmission Fluid Pump Control Circuit/Open) is: Failed auxiliary transmission fluid pump motor or seized pump
Typical repair costs for P2796 range from $300 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Transmission may overheat or experience inadequate lubrication during idle or stop-and-go driving. Can lead to transmission damage if driven extensively without repair.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2796 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission Lubrication System
Difficulty
Type
Generic (SAE)
Recommended Tools
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