Pinpoint Test G : DTCS P0B0D:00, P0C27:00, P0C28:00, P0C29:00, P0C2A:00, P175A
- Refer to Transmission Controls - 6R80
for schematic and connector information.
Normal Operation and Fault Conditions
The transmission fluid auxiliary pump is used to keep the transmission fluid circulating during extended drive times without engine charging. The transmission fluid auxiliary pump has an internal microprocessor and communicates with the C1551T over a PWM circuit with a frequency of 150 Hz and a duty cycle range of 10% to 90%. If the transmission fluid level is low or overfilled or there are any restrictions in the transmission lines, hoses (If vehicle is equipped with external lines or hoses) or cooler it may affect the transmission fluid pump operation.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition PCM P0B0D:00 Electric/Auxiliary Transmission Fluid Pump Motor Control Module: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (54% to 61% or 64% to 71%). The transmission fluid auxiliary pump has detected a pump over or under speed condition. The current flow through the pump was within specification. PCM P0C27:00 Electric/Auxiliary Transmission Fluid Pump "A" Motor Current Low: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (9% to 16%). The transmission fluid auxiliary pump has detected low current through the pump motor. The pump speed was within specification. PCM P0C28:00 Electric/Auxiliary Transmission Fluid Pump "A" Motor Current High: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (19% to 66%). The transmission fluid auxiliary pump has detected high current through the pump motor. The pump speed was within specification. PCM P0C29:00 Electric/Auxiliary Transmission Fluid Pump "A" Driver Circuit Performance: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (74% to 81%). The transmission fluid auxiliary pump has detected a performance issue with the pump driver. PCM P0C2A:00 Electric/Auxiliary Transmission Fluid Pump "A" Motor Stalled: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (35% to 41%). The transmission fluid auxiliary pump has detected 0 RPM pump speed. PCM P175A:00 Transmission Fluid Over Temperature Condition - Electric Transmission Fluid Pump Disabled: No Sub Type Information This DTC sets if the E-pump communication is OK. The frequency is between 130 Hz and 170 Hz and a valid duty cycle was detected (29% to 35%). The transmission fluid auxiliary pump has detected high fluid temperature in the pump and has temporarily disabled the pump to prevent pump damage. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires or ground and missing or damaged seals
- BJB fuses
- Transmission fluid cooler and lines
- Transmission fluid auxiliary pump
- G1 CHECK THE TRANSMISSION FLUID AUXILIARY PUMP POWER CIRCUITS
- Ignition OFF.
- Disconnect Transmission fluid auxiliary pump C1717.
- Ignition ON.
Is the voltage greater than 11 volts?
Yes GO to G2 No VERIFY BJB fuses 82 (30A) and 98 (15A) are OK. If fuses are OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify and repair an open circuit. If fuses are not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify and repair a short to ground. - G2 CHECK THE TRANSMISSION FLUID AUXILIARY PUMP GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead C1717-6 Ground
Is the resistance less than 3 ohms?
Yes GO to G3 No REPAIR the circuit - G3 CHECK THE TRANSMISSION FLUID LEVEL
- CHECK the transmission fluid level. REFER to: Transmission Fluid Level Check .
Is the transmission fluid level correct?
Yes If the vehicle is equipped with external lines and hoses going to the transmission fluid cooler, GO to G4 If not equipped with external lines, hoses, GO to G5 No CORRECT the transmission fluid to the proper level. - G4 CHECK THE TRANSMISSION FLUID LINES, HOSES AND COOLER
- Check the transmission fluid lines, hoses and transmission fluid cooler for obstructions or pinches (if equipped).
Are the transmission fluid lines, hoses and transmission fluid cooler free from obstructions or pinches?
Yes GO to G5 No REPAIR as necessary. - G5 CHECK THE TRANSMISSION FLUID AUXILIARY PUMP OPERATION
- Ignition ON.
- Using a diagnostic scan tool, COMMAND the transmission fluid auxiliary pump ON using PID, TRANS_PMP_CMD and vary the duty cycle from 20% to 90%,
Is the transmission fluid auxiliary pump operating and does the pump speed change as the duty cycle is increased or decreased?
Yes GO to G6 No INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump . - G6 RECHECK THE TRANSMISSION FLUID AUXILIARY PUMP OPERATION
- Clear diagnostic trouble codes (DTCs) and road test vehicle.
- Attempt to duplicate concern.
- Using a diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs).
Are DTCS P0B0D:00, P0C27:00, P0C28:00, P0C29:00, P0C2A:00, and/or P175A present after the test drive?
Yes INSTALL a new transmission fluid auxiliary pump. REFER to: Transmission Fluid Auxiliary Pump . No The system is operating correctly at this time.