Troubleshooting

DTC P0847 TRANSMISSION FLUID PRESSURE SENSOR/SWITCH "B" CIRCUIT LOW

DTC Detection Condition:

CIRCUIT DESCRIPTION

MONITOR DESCRIPTION

Monitor Strategy:

Typical Malfunction Thresholds:

Component Operating Range:

The master pressure sensor, installed in the Gear Shift Actuator (GSA), monitors hydraulic pressures of the Sequential Manual Transmission (SMT) fluid. This pressure is monitored as it comes from the Hydraulic Power Unit (HPU). This sensor's resistance varies depending on the amount of with the hydraulic pressure. The ECM applies a 5 V "pull-up" voltage to the sensor terminal and calculates the hydraulic pressure based on how much the sensor can "pull-down" this voltage. If the hydraulic pressure is high and the sensor resistance is high, the voltage will stay high. When the sensor resistance is low, the sensor will "pull-down" the voltage to a low level.

If the output voltage of the master pressure sensor is 4.75 V or more, or if the output voltage is less than 0.25 V, the transmission ECU will conclude that there is a malfunction of the pressure sensor or circuit, illuminate the MIL and set a DTC.

Wiring Diagram:

Step 1 - 2:

Step 3 - 4:

Step 5:

INSPECTION PROCEDURE

HINT: Read freeze frame data using hand-held tester or OBD II scan tool, as freeze frame records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, etc. at the time of the malfunction.