• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The following fault table gives examples of how hydraulic circuit problems and malfunctioning hard parts affect the transmission operation.
Component | Cause | DTCs | ||||
---|---|---|---|---|---|---|
1-2-3-4 and 3-5-R Clutch Housing Assembly | 1-2-3-4 clutch backing plate retaining ring not seated, causing the piston to over-travel and cut 1-2-3-4 clutch piston seal | P2723 | ||||
Fluid Pump Cover Assembly |
| P2723 | ||||
Lower Control Valve Body Assembly | Clutch select valve stuck off - debris, sediment, binding or scored bore | P2723 |
Gear | Shift SOL 1 | 1-2-3-4 CL PC SOL 5 N.L. | 2-6 CL PC SOL 4 N.L. | 3-5 REV CL PC SOL 2 N.H. | LOW REV 4-5-6 CL PC SOL 3 N.H. | Gear Ratio |
---|---|---|---|---|---|---|
Park | ON | OFF | OFF | OFF | ON | -- |
Reverse | ON | OFF | OFF | ON | ON | 2.940 |
Neutral | ON | OFF | OFF | OFF | ON | -- |
1st Braking | ON | ON | OFF | OFF | ON | 4.584 |
1st | OFF | ON | OFF | OFF | OFF | 4.584 |
2nd | OFF | ON | ON | OFF | OFF | 2.964 |
3rd | OFF | ON | OFF | ON | OFF | 1.912 |
4th | OFF | ON | OFF | OFF | ON | 1.446 |
5th | OFF | OFF | OFF | ON | ON | 1.000 |
6th | OFF | OFF | ON | OFF | ON | 0.746 |
Effective Final Drive Ratio - 6T40/45 - 3.17/3.87 For shift solenoid 1, "ON" = Solenoid Energized (Pressurized) "OFF" = Solenoid De-energized (No Pressure) For pressure control solenoids, "ON" = Pressurized, "OFF" = No Pressure |
The clutch pressure control (PC) solenoid 5 is part of the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly has no serviceable parts. The PC solenoid 5 is a normally high-pressure control solenoid which provides fluid pressure to the 1-2-3-4 clutch regulator valve. The TCM controls the solenoid pressure by regulating the exhaust fluid. When the TCM commands the solenoid off, the exhausting fluid is stopped and the 1-2-3-4 pressure is high. When commanded on, the clutch PC solenoid 5 regulates the amount of exhausting transmission fluid. Solenoid power is supplied by the TCM through a high side driver (HSD). The HSD protects the circuits and components that the TCM powers. Should the circuit overload the driver will shutdown. After the overload is removed the HSD reset. The TCM calculates gear ratio based on data from the automatic transmission input speed sensor (ISS) and the output speed sensor (OSS). The TCM compares the known transmission gear ratio to a calculated gear ratio for each commanded gear.
• | No ISS DTCs P0716 or P0717. |
• | No OSS DTCs P0722 or P0723. |
• | No IMS DTCs P1825 or P1915. |
• | The transmission input shaft speed is 60 RPM or greater. |
• | 1-2-3-4 clutch is commanded ON. |
• | No ISS DTCs P0716 or P0717. |
• | No OSS DTCs P0722 or P0723. |
• | No IMS DTCs P1825 or P1915. |
• | The transmission output shaft speed is 200 RPM or greater. |
• | 1-2-3-4 clutch is commanded OFF. |
The TCM detects an incorrect on-coming clutch gear ratio, or flare, when the 1-2-3-4 clutch is commanded ON for 4.0 seconds and the transmission input shaft speed is 33 RPM or greater from the anticipated input shaft speed.
The TCM detects an incorrect off-going clutch gear ratio, or tie-up, when the 1-2-3-4 clutch is commanded OFF for 1.2 seconds and the transmission input shaft speed is 40 RPM or less from the anticipated input shaft speed.
• | DTCs P2723 and P2724 are Type A DTCs. |
• | The TCM freezes transmission adaptive functions. |
• | DTC P2723 defaults to Reverse, Park, Neutral, 5th, or 6th gear. |
• | DTC P2724 defaults to Reverse, Park, Neutral, 1st, or 2nd gear. |
DTCs P2723 and P2724 are Type A DTCs.
DTC P2723 detects a neutral gear when the 1-2-3-4 clutch in enabled for 2nd and 6th gear.
DTC P2724 detects a clutch tie-up when the 1-2-3-4 clutch in on-coming.
• | When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. |
• | Use the scan tool to view the PC sol. 5 status and refer to the Transmission Fluid Pressure Switch Logic table to determine when a PC solenoid 5 switch should be active or inactive for a given gear. This will help to determine if the hydraulic circuit is functioning and if the PC solenoid or the valve train is in an incorrect position. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | DT-48616 Control Solenoid Test Plate |
• | DT-48616-10 Adapter Harness |
⇒ | If the DTC resets, go to Circuit/System Testing. |
⇒ | If the pressure is out of specification, correct this concern first. |
⇒ | If the DTC resets, continue on with testing. |
⇒ | If a concern is found, repair or replace the control solenoid (w/body and TCM) valve assembly. |
⇒ | If the solenoid is found to be leaking or stuck closed, replace the control solenoid (w/body and TCM) valve assembly. |
⇒ | If a concern if found in the valve body, repair or replace the valve body as necessary. |
⇒ | If a concern is found in the 1-2-3-4 clutch assembly, repair or replace as necessary. |
Operating the transmission under the following conditions will verify that the PC solenoid or a portion of the hydraulic control circuit is not functioning as it should.
Transmission Operating Conditions | Transmission Condition if PC Sol. 5 is Stuck OFF | DTC |
---|---|---|
Steady State: Gears 1st, 2nd, 3rd, 4th | Neutral | P2723 |
Garage Shift: Park/Neutral to Reverse/Drive | Neutral | P2723 |
Downshift: from gears 5th or 6th to 1st, 2nd, or 3rd | Neutral | P2723 |
Steady State: Gears 5th or 6th | 1, 2, 3, 4 | P2724 |
Upshift: from gears 1st, 2nd, 3rd, or 4th to 5th or 6th | 2nd or 6th | P2724 |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection . |
• | Refer to Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming. |
• | Perform the Service Fast Learn Adapts following all transmission related repairs. |
• | Perform the: |