Circuit Description
The 4-5 shift solenoid (SS) valve is a normally-closed exhaust valve. When the 1-2 and the 2-3 SS valves are both OFF, the 4-5 SS valve turns OFF to shift the transmission into 5th gear. When either of the other two shift solenoids are ON, the 4-5 SS turn OFF in order to enable powertrain braking. The 4-5 SS valve is attached to the control valve body, within the transmission.
The TCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0762 sets under two conditions:
| • | A stuck ON 4-5 SS valve |
| • | A stuck ON 4-5 shift valve |
If the TCM detects a 1-2-3-4-4 shift pattern, then DTC P0762 sets. DTC P0762 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0762 4-5 Shift Solenoid (SS) Valve Performance - No Fifth Gear
Conditions for Running the DTC
| • | No TP sensor DTC P0120. |
| • | No ISS DTCs P0716 or P0717. |
| • | No OSS DTCs P0722 or P0723. |
| • | No TCC stuck ON DTC P0742. |
| • | No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980. |
| • | No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826. |
| • | No engine torque delivered signal DTC P2637. |
| • | The engine run time is greater than 5 seconds. |
| • | The IMS range is not PARK, NEUTRAL or REVERSE. |
| • | The transmission fluid temperature is 20-130°C (68-266°F). |
| • | The throttle position is greater than 10 percent. |
| • | The input shaft speed is 200-6,800 RPM. |
| • | The output shaft speed is greater than 100 RPM. |
| • | The engine torque is greater than 36 N·m (27 lb ft). |
Conditions for Setting the DTC
The following conditions must occur twice during the same trip:
| • | The transmission control module (TCM) has commanded either 2nd or 3rd gear for 3 seconds or greater. |
| • | The TCM commands 5th gear and the resulting gear ratio is 0.98:1-1.03:1 for 3.5 seconds. |
Action Taken When the DTC Sets
| • | The TCM requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM inhibits Powertrain braking. |
| • | At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame. |
| • | The TCM stores DTC P0762 in TCM history. |
Conditions for Clearing the DTC
| • | The ECM turns OFF the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non 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
| • | If you clear DTC P0762, and then cannot reset DTC P0762, the following conditions may exist: |
| - | Fluid contamination |
| - | Plugged fluid circuits |
| - | Restricted fluid circuits |
| • | Refer to Shift Solenoid Valve State and Gear Ratio . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step verifies a 1-2-3-4-4 shift pattern.
-
This step tests for a mechanical or hydraulic condition causing the 4-5 SS valve to be stuck ON, or the circuit to be released.
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||
2 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Step 3 | Go to Transmission Fluid Check | ||||||||
Important:
Are the commanded gear and gear ratio within the specified range? | 4th 0.98:1-1.03:1 | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections | |||||||||
Refer to 4-5 Shift Solenoid Valve Replacement . Did you complete the repair? | -- | Go to Step 5 | -- | |||||||||
5 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 6 | Go to Step 2 | ||||||||
6 | 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? | -- | System OK |
