P1775
P1775-SOLENOID SWITCH VALVE LATCHED IN TCC POSITIONWiring Diagram:
When Monitored:
Prior to a shift into 1st gear.
Set Condition
Transmission temperature must be hot. DTC is set after six unsuccessful attempts to shift into 1st gear.
Possible Causes
- RELATED DTC P0841 PRESENT
- (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
- (T50) L/R PRESSURE SWITCH SENSE CIRCUIT OPEN
- (T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
- (T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
- INTERNAL TRANSMISSION
- POWERTRAIN CONTROL MODULE
Always perform the 40/41TE Pre-Diagnostic Troubleshooting procedure before proceeding.
Theory of Operation
The Solenoid Switch Valve, an internal, hydraulically operated valve, controls the direction of the transmission fluid when the LR solenoid is energized. When the solenoid switch valve is in the downshifted position and the LR solenoid is energized, fluid is directed to the LR element for 1st gear. When the solenoid switch valve is In the upshifted position (2nd, 3rd, and 4th gear) and the LR solenoid is energized, fluid is directed into the Lockup Switch Valve which controls the Torque Converter Clutch. When shifting into 1st gear, a special sequence is followed to insure solenoid switch valve movement into the downshifted position. The LR pressure switch is monitored to confirm switch valve movement. If the solenoid switch valve movement is not confirmed (i.e. no LR pressure when the LR solenoid is energized), 2nd gear is substituted for 1st. No 1st gear (2nd gear is substituted). The transmission Torque converter FEMCC operation is inhibited. MIL on after 5 minutes of substituted operation.
Diagnostic Test
1. DETERMINING IF RELATED DTCs ARE PRESENT
With the scan tool, check for other Transmission DTCs
Is the DTC P0841 present also?
Yes >> Refer to Testing and perform the appropriate diagnostic procedure(s). P0841
No >> Go To 2
2. CHECK TO SEE IF DTC P1775 IS CURRENT
With the scan tool, view DTCs.
Is the status Active for this DTC or is the STARTS SINCE SET counter 2 or less?
Yes >> Go To 3
No >> Go To 10
3. PCM AND WIRING
Turn the ignition off to the lock position.
Remove the Ignition Switch Feed fuse from the TIPM.
CAUTION: Removal of the Ignition Switch Feed fuse from the TIPM will prevent the vehicle from being started in gear.
WARNING: The Ignition Switch Feed fuse must be removed from the TIPM. Failure to do so can result in personal injury or death.
Install the Transmission Simulator, Miller tool #8333 and the Electronic Transmission Adapter kit 8333-1A.
Ignition on, engine not running.
With the Transmission Simulator, turn the Pressure Switch selector switch to L/R.
With the scan tool, monitor the L/R Pressure Switch State while pressing the Pressure Switch Test button.
Did the Pressure Switch state change from open to closed when the test button was pressed?
Yes >> Go To 4
No >> Go To 5
4. INTERNAL TRANSMISSION
If there are no possible causes remaining, view repair.
Repair
Repair internal transmission as necessary. Inspect the Solenoid Switch valve and repair or replace as necessary. If no problems are found, replace the Transmission Solenoid/Pressure Switch Assembly.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
5. (T16) TRANSMISSION CONTROL OUTPUT CIRCUIT OPEN
Turn the ignition off to the lock position.
Disconnect the Transmission Solenoid/Pressure Switch Assembly harness connector.
Disconnect the PCM C4 harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Ignition on, engine not running.
With the scan tool in the TIPM, actuate the TCM output.
Using a 12-volt test light connected to ground, check all (T16) Transmission Control Output circuits in the appropriate terminals of special tool #8815.
NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
Does the test light illuminate brightly on all Transmission Control Relay Output circuits?
Yes >> Repair the (T16) Transmission Control Output circuit for an open.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
No >> Go To 6.
6. (T50) L/R PRESSURE SWITCH SENSE CIRCUIT OPEN
Measure the resistance of the (T50) L/R Pressure Switch Sense circuit from the appropriate terminal of special tool #8815 to the Transmission Solenoid/Pressure Switch Assembly harness connector.
Is the resistance above 5.0 ohms?
Yes >> Repair the (T50) L/R Pressure Switch Sense circuit for an open.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
No >> Go To 7.
7. (T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO GROUND
Measure the resistance between ground and the (T50) L/R Pressure Switch Sense circuit.
Is the resistance below 5.0 ohms?
Yes >> Repair the (T50) L/R Pressure Switch Sense circuit for a short to ground.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
No >> Go To 8.
8. (T50) L/R PRESSURE SWITCH SENSE CIRCUIT SHORT TO VOLTAGE
Ignition on, engine not running.
While still actuating the TCM output in the TIPM with the scan tool, measure the voltage of the (T50) L/R Pressure Switch Sense circuit.
Is the voltage above 0.5 volts?
Yes >> Repair the (T50) L/R Pressure Switch Sense circuit for a short to voltage.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
No >> Go To 9
9. POWERTRAIN CONTROL MODULE
Using the schematics as a guide, inspect the wiring and connectors. Repair as necessary Pay particular attention to all power and ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace the Powertrain Control Module. With the scan tool perform QUICK LEARN.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
10. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Test drive and verify if the transmission is launching in 2nd gear and/or no TCC engagement.
With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.
Are there 2nd gear launches and/or no TCC engagement?
Yes >> Disassemble and inspect the Valve Body and repair or replace as necessary. If no problems are found in the Valve Body, replace the Transmission Solenoid Pressure Switch Assembly.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test
No >> Test Complete.