Circuit Description
The 1-2, 2-3, reverse shift solenoid valve (S3) is a normally-closed exhaust valve. The transmission control module (TCM) controls the 1-2, 2-3, reverse shift solenoid valve (S3) with an internal driver that pulls the solenoid control circuit to voltage. During a 3-4 gear shift, the TCM will turn the 1-2, 2-3, reverse shift solenoid valve (S3) OFF. If the 1-2, 2-3, reverse shift solenoid valve (S3) does not close, the U2 shift valve (392) will not move, and a 1.89:1 gear ratio will result in 4th gear, and a 1.45:1 gear ratio will result in 5th gear.
If the TCM detects a 1.89:1 gear ratio in 4th gear, or a 1.45:1 gear ratio in 5th gear, then DTC P0762 sets. DTC P0762 is a type A DTC.
Conditions for Running the DTC
| • | No TR switch DTC P0705. |
| • | No TFT DTCs P0711, P0712, or P0713. |
| • | No ISS DTC P0717. |
| • | No OSS DTC P0722. |
| • | No engine speed signal DTC P0727. |
| • | No TCC DTC P0741. |
| • | No solenoid circuit DTCs P0962, P0963, P0966, P0967, P0970, P0971, P0973, P0974, P0976, P0977, P0979, P0980, P0982, P0983, P0985, or P0986. |
| • | No engine torque signal DTC P1781. |
| • | No TP signal DTC P1791. |
| • | No CAN DTCs U2104 or U2105. |
| • | Trans. Protection Mode is OFF. |
| • | The brake switch is released. |
| • | The ignition voltage is 10.5-18 volts. |
| • | The transmission fluid temperature is 20°C (68°F) or greater. |
| • | The throttle position (TP) is 10 percent or greater. |
| • | The engine speed is 400 RPM or greater. |
| • | The OSS is 500 RPM or greater. |
| • | The commanded gear is 4 or 5. |
| • | The elapsed time since the most recent gear change is 0.5 seconds or greater. |
| • | The TR switch has been DRIVE for 8 seconds or greater. |
Conditions for Setting the DTC
| • | The 4th gear ratio is 1.89:1 for 12 seconds or, |
| • | The 5th gear ratio is 1.45:1 for 12 seconds. |
Action Taken When the DTC Sets
| • | The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL). |
| • | The TCM turns Trans. Protection Mode ON. The transmission will operate in third gear. |
| • | The TCM requests the ECM to limit engine torque to 150 N·m (111 lb ft). |
| • | The TCM inhibits the torque converter clutch (TCC) from applying. |
| • | The TCM freezes the transmission adaptive functions. |
| • | The TCM increases line pressure by 2.0 kg/cm 2 (14.2 psi) |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | The TCM stores DTC P0762 in TCM history. |
Conditions for Clearing the MIL/DTC
| • | The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the MIL/DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM. |
Diagnostic Aids
| • | Inspect the transmission fluid lines to the radiator. The lines may be pinched, plugged, or twisted. |
| • | Ask the customer about overloading the vehicle, or exceeding the trailer-towing limit. |
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 3.0L (L81) | ||||
2 | Inspect for correct transmission fluid level. Refer to Transmission Fluid Check . Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Step 4 | Go to Step 3 | ||||
3 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 4 | ||||
4 |
Important:
Is the 4th gear ratio equal to the specified value? | 1.89:1 | Go to Step 5 | Go to Intermittent Conditions in Engine Controls - 3.0L (L81) | ||||
5 | Drive the vehicle in 5th gear and record the gear ratio. Is the 5th gear ratio equal to the specified value? | 1.45:1 | Go to Step 6 | Go to Intermittent Conditions in Engine Controls - 3.0L (L81) | ||||
6 |
Does shift solenoid 3 click when commanded ON and OFF? | -- | Go to Step 7 | Go to Step 12 | ||||
7 | Perform a line pressure test. Refer to Line Pressure Check . Is the action complete? | -- | Go to Step 8 | -- | ||||
8 |
Did you find excessive amounts of sediment? | -- | Go to Step 11 | Go to Step 9 | ||||
9 | Inspect the control valve body assembly (39) for the following conditions:
Refer to Control Valve Body Assembly Disassemble . Did you find any of the above conditions? | -- | Go to Step 13 | Go to Step 10 | ||||
10 | Has the control valve body been serviced within the past 3 months or 4,828 km (3,000 miles)? | -- | Go to Step 11 | Go to Step 13 | ||||
11 | Inspect the following items:
Refer to 4-5 Clutch Drum Assembly Assemble and 2nd Clutch Assemble . Did you find any of the above conditions? | -- | Go to Step 14 | -- | ||||
12 | Replace the 1-2, 2-3, Reverse shift solenoid valve assembly (S3). Refer to Control Valve Body Assembly Disassemble . Is the replacement complete? | -- | Go to Step 16 | -- | ||||
13 | Repair or replace the control valve body assembly (39). Refer to Control Valve Body Replacement . Is the action complete? | -- | Go to Step 16 | -- | ||||
14 | Repair or replace the transmission. Refer to Transmission Replacement . Is the action complete? | -- | Go to Step 15 | -- | ||||
15 |
Important: The Reset Trans Adapts function will clear all adapt cells. This may affect transmission performance. The TCM will update the adapt cell values as the vehicle is driven.
Did you complete the above procedures? | -- | Go to Step 16 | -- | ||||
16 | Perform the following procedure in order to verify the repair:
Does the DTC reset? | -- | Go to Step 2 | Go to Step 17 | ||||
17 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 3.0L (L81) | System OK |
