2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1592

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1592

Circuit/System Description

The shift control solenoid assembly (SLC1, SLC2, SLC3, SLB1) and the line pressure control solenoid (SLT) are installed on the front valve body.

The solenoids linearly control hydraulic pressure in response to signals output from the transmission control module (TCM). SLC1, SLC2, SLC3,

SLB1 controls hydraulic pressure to the clutches (C1, C2, C3) and brake (B1) for smooth shifting. According to each shift control solenoid

assembly, the transmission shifts from 1st gear to 6th gear and vice versa. As a fail-safe function, if any shift control solenoid assembly abnormality

occurs, the TCM will disable the current to the solenoids.

Conditions for Running the DTC

* The ignition voltage is 10.2-15.5 V.

* The engine speed is greater than 400 RPM for 2 s.

* The transmission is not in emergency mode.

* TCM communication is normal.

* Transmission fluid temperature is higher than 20掳C (68掳F).

* DTCs P0716. P0717, P0721 and P0722 are not set.

Conditions for Setting the DTC

* Driving in D range, 6th gear.

* Output speed more than 500 RPM.

* Throttle position more than 10%.

* Measured gear ratio deviates more than 20% from expected ratio.

* Measured gear ratio deviates within 4% from 4th or 5th gear ratio.

* Determined after 12 times lasting 1 s or more.

Action Taken When the DTC Sets

* DTC P0729 is a Type C DTC.

* Torque limitation in "D" range 150 Nm (110 lb ft), in "R" range 170 Nm (125 lb ft).

* The TCM freezes transmission adaptive functions.

* The TCM turns OFF all solenoids.

* The TCM allows the vehicle to operate only in the second gear and "R" range after a stop.

Conditions for Clearing the DTC

* DTC P0729 is a Type C DTC.

* Measured gear ratio deviates less than 4% from expected ratio.

Diagnostic Aids

Ensure the transmission fluid level, color and odor is correct and there are no leaks. If there are any other transmission DTCs set, diagnose those