The P2796: Auxiliary Transmission Fluid Pump Control Circuit/Open code indicates that there is an open circuit detected in the control circuit for the auxiliary transmission fluid pump. This could be due to a faulty auxiliary transmission fluid pump, damaged wiring, a poor connection, or an issue with the control module. This pump is critical for ensuring adequate transmission fluid flow, especially during stop-start operations or when additional cooling is needed.
P2796 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P2796: Auxiliary Transmission Fluid Pump Control Circuit/Open |
| Is it serious? | Yes, an open circuit in the auxiliary transmission fluid pump control can lead to improper fluid circulation, causing overheating and potentially damaging the transmission. |
| Possible causes | – Open circuit in auxiliary transmission fluid pump control – Faulty pump or wiring – Control module issues |
| How to diagnose? | – Inspect and test the auxiliary transmission fluid pump control circuit – Check wiring and connectors – Verify control module functionality – Replace faulty pump or components as needed |
P2796 Meaning
The P2796: Auxiliary Transmission Fluid Pump Control Circuit/Open code means that the transmission control module (TCM) has detected an open or incomplete circuit within the auxiliary transmission fluid pump control system. This could be due to damaged wiring, a disconnected component, or a faulty control module. The auxiliary transmission fluid pump helps regulate fluid flow and temperature within the transmission, which is essential for maintaining optimal performance, especially under varying load conditions.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to determine if there are any additional related codes. Other codes may help pinpoint whether there are broader issues affecting the transmission system, including electrical or control module problems. | OBD-II Scanner |
| Inspect the Auxiliary Transmission Fluid Pump Control Circuit | Perform a visual inspection of the auxiliary transmission fluid pump control circuit. Look for any visible signs of damage, such as disconnected connectors, worn wiring, or visible breaks in the circuit. Make sure that all components are properly connected. | Flashlight, Safety Gloves |
| Measure Voltage in Control Circuit | Use a multimeter to measure the voltage across the auxiliary transmission fluid pump control circuit. Compare the measured voltage to the manufacturer’s specifications to verify that power is reaching the pump as expected. An open circuit is indicated by no voltage reading or an inconsistent value. | Multimeter, Manufacturer Specifications |
| Check for Open Circuits or Continuity | Test the wiring connected to the auxiliary transmission fluid pump using a multimeter set to measure continuity. Verify that there are no open circuits in the wiring between the control module and the pump. An open circuit indicates a broken wire or poor connection that must be repaired or replaced. | Multimeter |
| Inspect Wiring and Connectors | Check all wiring and connectors associated with the auxiliary transmission fluid pump. Look for corroded, damaged, or disconnected wires. Ensure all connectors are securely attached and free from dirt or corrosion, as this can disrupt circuit continuity. | Flashlight, Safety Gloves |
| Test the Auxiliary Transmission Fluid Pump | Disconnect the auxiliary transmission fluid pump and use a multimeter to check its resistance. Compare this to the manufacturer’s specifications to determine if the pump is faulty. Replace the pump if it does not meet these specifications. | Multimeter, Manufacturer Specifications |
| Verify Control Module Functionality | Use a diagnostic tool to check if the transmission control module (TCM) is properly sending signals to the auxiliary pump. A malfunctioning TCM may not provide the correct signal to activate the pump, leading to an open circuit condition. If the TCM is faulty, reprogramming or replacement may be required. | Diagnostic Tool, Manufacturer Software |
| Inspect Relay and Fuses | Check the relay and fuses related to the auxiliary transmission fluid pump control circuit. A blown fuse or malfunctioning relay could cause an open circuit, preventing power from reaching the pump. Replace any defective components as needed. | Multimeter, Fuse Puller |
| Replace Faulty Components as Needed | Replace any faulty components identified during diagnostics, such as the auxiliary transmission fluid pump, faulty wiring, connectors, or a malfunctioning control module. Ensure that all parts meet manufacturer specifications for optimal performance and reliability. | Replacement Auxiliary Pump, Wiring Repair Kit, Control Module |
| Clear the Code and Test Drive | After completing repairs, use an OBD-II scanner to clear the P2796 code. Take the vehicle for a test drive to confirm that the auxiliary transmission fluid pump is operating correctly and that the transmission maintains adequate fluid flow. Monitor for any warning lights or irregular shifting behavior. | OBD-II Scanner |
| Recheck for Codes | Perform a final scan after the test drive to ensure that the P2796 code has not returned. If the code persists, further diagnostics may be required to identify ongoing issues with the pump control circuit. | OBD-II Scanner |
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