What Does P0C29 Mean?
DTC P0C29 indicates the auxiliary transmission fluid pump driver circuit is not performing within expected parameters. The driver circuit, typically a MOSFET or relay inside the control module, modulates power to the pump motor. A performance fault means the driver is not switching correctly, has degraded over time, or the circuit response does not match the commanded output.
Common Causes
30%
Degraded MOSFET or driver transistor in the pump control module
25%
High resistance in the pump motor circuit causing driver feedback mismatch
20%
Intermittent connection at the control module or pump motor connector
15%
Control module internal power supply issue affecting driver voltage
10%
EMI interference causing erratic driver circuit behavior
Diagnostic Steps
1
Use a scan tool to monitor the commanded duty cycle versus actual pump motor feedback to identify the performance deviation.
2
Inspect all connectors in the auxiliary pump circuit for intermittent connections, corrosion, or loose terminals.
3
Measure voltage drop across the driver circuit under load to identify excessive resistance.
4
Check for aftermarket electronics or improperly routed wiring that could cause electromagnetic interference.
5
If the driver circuit within the control module is suspect, replace the auxiliary pump control module.
Estimated Repair Cost
$200 - $900
Parts + labor, varies by vehicle and location
DTC P0C29 indicates the auxiliary transmission fluid pump driver circuit is not performing within expected parameters. The driver circuit, typically a MOSFET or relay inside the control module, modulates power to the pump motor. A performance fault means the driver is not switching correctly, has de...
The most common cause of P0C29 (Auxiliary Transmission Fluid Pump Driver Circuit Performance) is: Degraded MOSFET or driver transistor in the pump control module
Typical repair costs for P0C29 range from $200 to $900, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A degraded driver circuit may cause erratic or insufficient pump operation, leading to inconsistent transmission fluid pressure. This can result in harsh or delayed shifts and potential transmission overheating during hybrid operating modes. Schedule repair soon.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0C29 to identify the root cause.
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Quick Info
Category
Powertrain
System
Transmission / Hybrid Drivetrain
Difficulty
Type
Generic (SAE)
Recommended Tools
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