Range Reference
| Range | Park | Reverse | Neutral | OD | D | 2 | 1 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gear | 1st | 2nd | 3rd | 4th | 1st | 2nd | 3rd | 1st** | 2nd | 1st | 2nd*** | |||
| 1-2 Shift Solenoid | ON* | ON* | ON* | ON | OFF | OFF | ON | ON | OFF | OFF | ON | OFF | ON | OFF |
| 2-3 Shift Solenoid | ON* | ON* | ON* | ON | ON | OFF | OFF | ON | ON | OFF | ON | ON | ON | ON |
| 2-4 Band | A | A | A | A | A | |||||||||
| Reverse Input Clutch | A | |||||||||||||
| Overrun Clutch | A | A | A | A | A | |||||||||
| Forward Clutch | A | A | A | A | A | A | A | A | A | A | A | |||
| Forward Sprag Clutch Assembly | H | H | H | H | H | H | H | H | H | H | ||||
| 3-4 Clutch | A | A | A | |||||||||||
| Lo/Roller Clutch | H | H | H | H | ||||||||||
| Lo/Rev Clutch | A | A | A | |||||||||||
| A = Applied H = Holding ON = The solenoid is energized. OFF = The solenoid is de-energized. *Shift Solenoid state is a function of vehicle speed and may change if the vehicle speed increases sufficiently in Park, Reverse or Neutral. However, this does not affect the operation of the transmission. **Manual Second-First gear is electronically prevented under normal operating conditions. ***Manual First-Second gear is only available above approximately 48-56 km/h (30-35 mph). | ||||||||||||||
Range Reference Table
Shift Solenoid Valve State and Gear Ratio
| Gear | 1-2 Shift Solenoid | 2-3 Shift Solenoid | Gear Ratio |
|---|---|---|---|
| 1 | ON | ON | 3.059:1 |
| 2 | OFF | ON | 1.625:1 |
| 3 | OFF | OFF | 1.000:1 |
| 4 | ON | OFF | 0.696:1 |
Shift Solenoid Valve State And Gear Ratio 4L60-E
Shift Speed
| 1-2 Upshift @ +/- 250 RPM Output Shaft Speed | 2-3 Upshift @ +/-250 RPM Output Shaft Speed | 3-4 Upshift @ +/- 250 RPM Output Shaft Speed | 1-2 Upshift @ WOT +/- 250 RPM, Output Shaft Speed | 2-3 Upshift @ WOT +/- 250 RPM, Output Shaft Speed | WOT 3-1 Downshift +/- 100 RPM, Output Shaft Speed | MIN TCC Apply @ 12% (RPM) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % of TPS | 12 | 25 | 50 | 12 | 25 | 50 | 12 | 25 | 50 | ||||||
| Trans Cal | Body | Axle | |||||||||||||
| 5.3L (LM4) | |||||||||||||||
| D | S/T | 3.42/3.73 | 430 | 650 | 1100 | 815 | 1080 | 1800 | 1200 | 1640 | 2700 | 1830 | 3190 | 1360 | 1200 |
Shift Speed
Transmission Range Switch Logic
| Gear Selector Position | Signal A | Signal B | Signal C | Signal P |
|---|---|---|---|---|
| Park (P) | LOW | HI | HI | LOW |
| Reverse (R) | LOW | LOW | HI | HI |
| Neutral (N) | HI | LOW | HI | LOW |
| Drive 4 (OD) | HI | LOW | LOW | HI |
| Drive 3 (3) | LOW | LOW | LOW | LOW |
| Drive 2 (2) | LOW | HI | LOW | HI |
| Drive 1 (1) | HI | HI | LOW | LOW |
| HI = Ignition voltage LOW = 0 volts | ||||
Transmission Range Switch Logic
Line Pressure
| Pressure Control Solenoid Current (Amp) | Approximate Line Pressure (PSI) |
|---|---|
| 0.00 | 169-195 |
| 0.10 | 167-194 |
| 0.20 | 161-190 |
| 0.30 | 155-186 |
| 0.40 | 144-177 |
| 0.50 | 133-167 |
| 0.60 | 120-153 |
| 0.70 | 102-138 |
| 0.80 | 83-119 |
| 0.90 | 62-97 |
| 1.00 | 53-69 |
| 1.10 | 53-68 |
Line Pressure (4L60-E)
Component Resistance
| Component | Pass Thru Pins | Resistance at 20° C (68° F) | Resistance at 100° C (212° F) | Resistance to Ground (Case) |
|---|---|---|---|---|
| 1-2 Shift Solenoid Valve | A, E | 19-24 ohms | 24-31 ohms | Greater than 250 K ohms |
| 2-3 Shift Solenoid Valve | B, E | 19-24 ohms | 24-31 ohms | Greater than 250 K ohms |
| TCC Solenoid Valve | T, E | 21-26 ohms | 26-33 ohms | Greater than 250 K ohms |
| TCC PWM Solenoid Valve | U, E | 10-11 ohms | 13-15 ohms | Greater than 250 K ohms |
| 3-2 Shift Solenoid Valve Assembly | S, E | 20-24 ohms | 29-32 ohms | Greater than 250 K ohms |
| Pressure Control Solenoid Valve | C, D | 3-5 ohms | 4-7 ohms | Greater than 250 K ohms |
| *Transmission Fluid Temperature (TFT) Sensor | M, L | 3088-3942 ohms | 159.3-198.0 ohms | Greater than 10 M ohms |
| Vehicle Speed Sensor | A, B VSS CONN | 1377-2220 ohms | 1800-3355 ohms | Greater than 10 M ohms |
| IMPORTANT: The resistance of this device is necessarily temperature dependent and will therefore vary far more than any other device. Refer to Transmission Fluid Temperature (TFT) Sensor Specifications . | ||||
| IMPORTANT |
|---|
| The resistance of this device is necessarily temperature dependent and will therefore vary far more than any other device. Refer to Transmission Fluid Temperature (TFT) Sensor Specifications . |
Component Resistance
Tools Required
J 41364-A Neutral Position Adjustment Tool. See Special Tools and Equipment .
- J 43909 Selector Shaft Seal Installer. See «Special Tools and Equipment»(ref-187837-S16803645262005090100000) .
- J 43911 Selector Shaft Seal Remover. See «Special Tools and Equipment»(ref-187837-S16803645262005090100000) .
J 28458 Seal Protector Retainer Installer. See Special Tools and Equipment .
J 21366 Converter Holding Strap
How to Use This Section
This section provides the following information
- General diagnosis information on transmissions
- Procedures for diagnosing the Hydra-matic transmission
When you diagnose any condition of the Hydra-matic transmission, begin with A Diagnostic Starting Point. This procedure indicates the proper path of diagnosing the transmission by describing the basic checks. This procedure will then refer you to the locations of specific checks. After you have determined the cause of a condition, refer to Repair Instructions for repair procedures. If the faulty component is not serviceable without removing the transmission from the vehicle, refer to Unit Repair for repair information.
Basic Knowledge
Note. Do not, under any circumstances, attempt to diagnose a powertrain condition without basic knowledge of this powertrain. If you perform diagnostic procedures without this basic knowledge, you may incorrectly diagnose the condition or damage the powertrain components.
You must be familiar with some basic electronics in order to use this section of the service manual. You should also be able to use the following special tools
- A digital multimeter (DMM)
- A circuit tester
- Jumper wires or leads
- A line pressure gage set
Transmission Adaptive Functions
The 4L60-E transmission utilizes a line pressure control system during upshifts to compensate for the normal wear of transmission components. By adjusting the line pressure, the PCM can maintain acceptable transmission shift times. This process is known as "adaptive learning" or "shift adapts" and is similar to the closed loop fuel control system used for the engine.
In order for the PCM to perform a "shift adapt," it must first identify if an upshift is acceptable to analyze. For example, upshifts that occur during cycling of the A/C compressor or under extreme throttle changes could cause the PCM to incorrectly adjust line pressure. When an upshift is initiated, a number of contingencies, such as throttle position, transmission temperature, and vehicle speed, are checked in order to determine if the actual shift time is valid to compare to a calibrated desired shift time. If all the contingencies are met during the entire shift, then the shift is considered valid and the adapt function may be utilized if necessary.
Once an adaptable shift is identified, the PCM compares the actual shift time to the desired shift time and calculates the difference between them. This difference is known as the shift error. The actual shift time is determined from the time that the PCM commands the shift to the start of the engine RPM drop initiated by the shift. If the actual shift time is longer than the calibrated desired shift time, a soft feel or slow engagement, then the PCM decreases current to the pressure control (PC) solenoid in order to increase line pressure for the next, same, upshift under identical conditions. If the actual shift time is shorter than the calibrated desired shift time, a firm engagement, then the PCM increases current to the PC solenoid in order to decrease line pressure for the next, same, upshift under identical conditions.
The purpose of the adapt function is to automatically compensate the shift quality for the various vehicle shift control systems. It is a continuous process that will help to maintain optimal shift quality throughout the life of the vehicle.
Clearing Transmission Adaptive Pressure (TAP)
Transmission adaptive pressure (TAP) information is displayed and may be reset using a scan tool.
The adapt function is a feature of the PCM that either adds or subtracts line pressure from a calibrated base line pressure in order to compensate for normal transmission wear. The TAP information is divided into 13 units, called cells. The cells are numbered 4 through 16. Each cell represents a given torque range. TAP cell 4 is the lowest adaptable torque range and TAP cell 16 is the highest adaptable torque range. It is normal for TAP cell values to display zero or negative numbers. This indicates that the PCM has adjusted line pressure at or below the calibrated base line pressure.
Updating TAP information is a learning function of the PCM designed to maintain acceptable shift times. It is not recommended that TAP information be reset unless one of the following repairs has been made
- Transmission overhaul or replacement
- Repair or replacement of an apply or release component, clutch, band, piston, servo
- Repair or replacement of a component or assembly which directly affects line pressure
Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, the PCM will need to relearn TAP values. Transmission performance may be affected as new TAPs are learned. Learning can only take place when the PCM has determined that an acceptable shift has occurred. The PCM must also relearn TAP values if it is replaced.
Scheme 105
The 1-2 and 2-3 shift solenoid valves (also called A and B solenoids) are identical devices that control the movement of the 1-2 and 2-3 shift valves. The 3-4 shift valve is not directly controlled by a shift solenoid. The solenoids are normally-open exhaust valves that work in 4 combinations to shift the transmission into different gears.
The powertrain control module (PCM) energizes each solenoid by grounding the solenoid through an internal quad driver. This sends current through the coil winding in the solenoid and moves the internal plunger out of the exhaust position. When ON, the solenoid redirects fluid to move a shift valve.
| IMPORTANT | The manual valve hydraulically can override the shift solenoids. Only in D4 do the shift solenoid states totally determine what gear the transmission is in. In the other manual valve positions, the transmission shifts hydraulically and the shift solenoid states CATCH UP when the throttle position and the vehicle speed fall into the correct ranges. |
The PCM-controlled shift solenoids eliminate the need for TV and governor pressures to control shift valve operation.
Scheme 106
The 3-2 shift solenoid valve assembly is a normally-closed, 3-port, ON/OFF device that is used in order to improve the 3-2 downshift. The solenoid regulates the release of the 3-4 clutch and the 2-4 band apply.
Scheme 107
The transmission pressure control solenoid is an electronic pressure regulator that controls pressure based on the current flow through its coil winding. The magnetic field produced by the coil moves the solenoid's internal valve which varies pressure to the pressure regulator valve.
The PCM controls the pressure control solenoid by commanding current between 0.1-1.1 amps. This changes the duty cycle of the solenoid, which can range between 5-95 percent, typically less than 60 percent. High amperage (1.1 amps) corresponds to minimum line pressure, and low amperage (0.1 amp) corresponds to maximum line pressure, if the solenoid loses power, the transmission defaults to maximum line pressure.
The PCM commands the line pressure values, using inputs such as engine speed and throttle position sensor voltage.
The pressure control solenoid takes the place of the throttle valve or the vacuum modulator that was used on past model transmissions.
Scheme 108
The torque converter clutch (TCC) solenoid valve is a normally-open exhaust valve that is used to control torque converter clutch apply and release. When grounded (energized) by the powertrain control module (PCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the TCC solenoid valve into the apply position.
Scheme 109
The torque converter clutch pulse width modulation solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the torque converter clutch (TCC) apply and release. This solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid valve provides a smooth engagement of the torque converter clutch by operating during a duty cycle percent of ON time.
Scheme 110
| IMPORTANT | Seven valid combinations and two invalid combinations are available from the TFP manual valve position switch. Refer to the Transmission Fluid Pressure (TFP) Manual Valve Position Switch Logic table for valid/invalid combinations for range signal circuits A, B and C. |
The transmission fluid pressure (TFP) manual valve position switch consists of five pressure switches (two normally-closed and three normally-open) on the control valve body that sense whether fluid pressure is present in five different valve body passages. The combination of switches that are open and closed is used by the PCM in order to determine the actual manual valve position. The TFP manual valve position switch, however, cannot distinguish between PARK and NEUTRAL because the monitored valve body pressures are identical in both cases.
The switches are wired to provide three signal lines that are monitored by the PCM. These signals are used to help control line pressure, torque converter clutch apply and shift solenoid valve operation. Voltage at each of the signal lines is either zero or twelve volts.
In order to monitor the TFP manual valve position switch operation, the PCM compares the actual voltage combination of the switches to a TFP combination table stored in its memory.
The TFP manual valve position switch signal voltage can be measured from each pin-to-ground and compared to the combination table. On the automatic transmission (AT) wiring harness assembly, pin N is signal A, pin R is signal B, and pin P is signal C. With the AT wiring harness assembly connected and the engine running, a voltage measurement of these three lines will indicate a high reading (near 12 volts) when a circuit is open, and a low reading (zero volts) when the circuit is switched to ground.
The transmission fluid temperature (TFT) sensor is part of the TFP manual valve position switch assembly.
Scheme 111
The vehicle speed sensor (VSS) assembly provides vehicle speed information to the PCM. The VSS assembly is a permanent magnet (PM) generator. The PM generator produces a pulsing AC voltage as rotor teeth on the transmission output shaft pass through the sensor's magnetic field. The AC voltage level and the number of pulses increase as the speed of the vehicle increases. Output voltage varies with speed from a minimum of 0.5 volts at 100 RPM to more than 100 volts at 8,000 RPM. The PCM converts the pulsing voltage to vehicle speed. The PCM uses the vehicle speed signal to determine shift timing and TCC scheduling.