Transmission Outputs

Shift Solenoids 

6R80 has 5 shift solenoids:

1. SSA - a Variable Force Solenoid (VFS) that controls CB1234 (a brake clutch, grounds an element to the case, that is on in 1st, 2nd, 3rd and 4th gear)
2. SSB - a VFS that controls C35R (a rotating clutch on in 3rd, 5th and Reverse)
3. SSC - a VFS that controls CB26 (a brake clutch on in 2nd and 6th gear)
4. SSD - a VFS that controls either CBLR (a brake clutch on in 1st gear with engine braking and Reverse) or C456 (a rotating clutch on in 4th, 5th and 6th gear)
5. SSE - an On/Off solenoid that controls the multiplexing of SSD between CBLR and C456.

Output circuits are checked for opens, short to ground and short to power faults (codes listed in that order) by the PCM by monitoring the status of a feedback circuit from the output driver (SSA P0750, P0973, P0974; SSB P0755, P0976, P0977; SSC P0760, P0979, P0980; SSD P0765, P0982, P0983; SSE P0770).

The shift solenoids are also functional tested for stuck on and stuck off failures. This is determined by vehicle inputs such as gear command, and achieved gear (based on turbine and output speed). In general the shift solenoid malfunction codes actually cover the entire clutch system (solenoid, valves, and the clutch itself) since using ratio there is no way to isolate the solenoid from the rest of the clutch system.

For SSA thru SSD Diagnostics will isolate the fault into clutch functionally (non-electrical) failed off (SSA P0751, SSB P0756, SSC P0761, SSD P0766) and clutch functionally failed on (SSA: P0752, SSB: P0757, SSC: P0762, SSD: P0767). The On/Off solenoid (SSE) controls the multiplexing of SSD between CBLR and C456 clutches. Using ratio we can determine if the multiplex valve is in the wrong position, but cannot be sure if the failure is due to the solenoid or a stuck valve. The multiplex valve is tested for stuck in default position (P0771, includes SSE stuck off) and stuck in spring compressed position (P0772, includes SSE stuck on) failures.

Gear ratio errors: 

If ratio errors are detected that do not match an expected pattern for a failed solenoid then gear ratio error fault codes (1st gear - P0731, 2nd gear - P0732, 3rd gear - P0733, 4th gear - P0734, 5th gear - P0735 or 6th gear - P0729) will be stored.

Torque Converter Clutch 

The Torque Converter Clutch (TCC) Solenoid output circuit is a duty-cycled output that is checked electrically for open circuit, short circuit to ground, and short circuit to power by monitoring the status of a feedback circuit from the output driver (P0740, P2763, P2764). If the TCC pressure is high and the engine torque is low, the TCC should be fully applied or have a controlled amount of slippage. If the slip exceeds a threshold, a fault is stored (P0741).

Pressure Control 

The Pressure Control solenoid is a variable force solenoid that controls line pressure in the transmission. The Pressure Control solenoid output circuit is a duty-cycled output that is checked electrically for short circuit to ground or short circuit to battery by monitoring the status of a feedback circuit from the output driver (P0962, P0963).

High Side Actuator Control Circuit 

The TCM has a high side actuator supply control circuit that can be used to remove power from all 7 solenoids and the external Reverse Light Relay simultaneously. If the high side actuator control circuit is deactivated, all 7 solenoids and the external Reverse Light Relay will be electrically turned off, providing Park, Reverse, Neutral, and 3M/5M (in all forward ranges) with maximum line pressure, based on the selected transmission range. The actuator control circuit is tested for open circuits. (P0657).

ADLER (chip that controls all 7 solenoids) diagnostics: 

The solenoids are controlled by an ADLER chip. The main micro sends commanded solenoid states to the ADLER, and receives back solenoid circuit fault information.

If communication with the ADLER is lost a P1636 fault code will be stored. If this failure is detected the states of the solenoids are unknown, so the control system will open the high side switch (removes power from all the solenoids), providing P, R, N and 5M with open TCC and max line pressure.

TRID Block 

The TRID block is a portion of flash memory that contains solenoid characterization data tailored to the specific transmission to improve pressure accuracy.

The TRID block is monitored for two failures:

1. TRID block checksum error / incorrect version of the TRID (P163E)
2. TRID block not programmed (P163F)

If the TRID block is unavailable FMEM action limits operation to 1st and 3rd gear until the issue is correct.