Automatic Transmission - 4L60-E/4L65-E (Service & Replacement): Overview GMC Savana H2500

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 1. This step determines if the scan tool is receiving power through the DLC connector.
2. 2. The MIL should illuminate whenever the ignition is ON and the engine is not running.
3. 3. This step determines if the PCM is transmitting class 2 serial data to the DLC and that the class 2 data circuit is not open or shorted.
4. 4. This step determines if a DTC is current or stored in history.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step inspects for air flow restrictions or damage which may result in the transmission overheating.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step tests the VSS assembly circuit.
2. 4. This step tests the integrity of the VSS assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step tests the VSS assembly circuit.
2. 4. This step tests the integrity of the VSS assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 5. By disconnecting the transmission range switch, the ground path of all TR switch circuits would be removed and the PCM would recognize all circuits as open. The scan tool will display HI for all range signals.
2. 6. This step tests TR switch wiring for an open or the lack of the signal voltage from the PCM.
3. 7. This step tests TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal A should change to LOW.
4. 8. This step tests TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal B should change to LOW.
5. 9. This step tests TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal C should change to LOW.

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The numbers below refer to the step numbers on the diagnostic table.

1. 5. This step tests for an intermittent short or open condition in the engine wiring harness. The test lamp is used as a resistor in the circuit.
2. 6. This step determines if the PCM or the TFT sensor is causing a steady, unchanging TFT reading.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step tests for a short to ground condition.
2. 4. This step tests for an internal fault within the transmission by creating an open.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step verifies a condition in the TFT sensor circuit.
2. 4. This step simulates a TFT sensor DTC P0712. If the PCM recognizes low signal voltage, high temperature, the PCM and wiring are functioning normally.
3. 5. This step tests the TFT sensor and automatic transmission (AT) wiring harness assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step isolates the brake switch as a source for setting the DTC.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step isolates the brake switch as a source for setting the DTC.

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The numbers below refer to the step numbers on the diagnostic table.

1. 4. This step tests for voltage to the solenoid.
2. 5. This step tests the ability of the PCM and wiring to control the ground circuit.
3. 7. This step tests the resistance of the TCC solenoid valve and the automatic transmission (AT) wiring harness assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step inspects for excessive TCC slip when the TCC is commanded ON.
2. 3. This step inspects for possible causes of no TCC apply.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests the hydraulic state of the TCC. When the PCM commands the TCC solenoid valve OFF, the slip speed should increase.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests the ability of the PCM to command the PC solenoid valve.
2. 3. This step tests the PC solenoid valve and automatic transmission wiring harness assembly for incorrect resistance.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests that the PCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests that the PCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

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The numbers below refer to the step numbers on the diagnostic table.

1. 4. This step tests the function of the 1-2 SS valve and the automatic transmission (AT) wiring harness assembly.
2. 5. This step tests for power to the 1-2 SS valve from the ignition through the fuse.
3. 6. This step tests the ability of the PCM and of the wiring to control the ground circuit.
4. 8. This step measures the resistance of the AT wiring harness assembly and of the 1-2 SS valve.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests that the PCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests that the PCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

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The numbers below refer to the step numbers on the diagnostic table.

1. 4. This step tests the function of the 2-3 SS valve and the automatic transmission (AT) wiring harness assembly.
2. 5. This step tests for power to the 2-3 SS valve from the ignition through the fuse.
3. 6. This step tests the ability of the PCM and of the wiring to control the ground circuit.
4. 8. This step measures the resistance of the AT wiring harness assembly and of the 2-3 SS valve.

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The item numbers below refer to the step numbers on the diagnostic table.

1. 4. This step tests the ability of the PCM to control the solenoid.
2. 5. This step tests for voltage to the solenoid.
3. 6. This step tests the ability of the PCM and the wiring to control the ground circuit.
4. 8. This step measures the resistance of the automatic transmission wiring harness assembly and the 3-2 SS valve assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step tests the torque converter for slippage while in a commanded lock-up state.

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The numbers below refer to the step numbers on the diagnostic table.

1. 3. This step compares the indicated range signal to the selected manual valve position.
2. 5. This step tests for correct voltage from the PCM to the AT inline 20-way connector.

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The numbers below refer to the step numbers on the diagnostic table.

1. 4. This step tests for voltage to the solenoid.
2. 5. This step tests the ability of the PCM and wiring to control the ground circuit.
3. 7. This step tests the resistance of the TCC PWM solenoid valve and the automatic transmission wiring harness assembly.

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The numbers below refer to the step numbers on the diagnostic table.

1. 4. By disconnecting the TR switch, the ground path of all TR switch circuits is removed and the PCM should recognize all circuits as open. The scan tool should display HI for all range signal states.
2. 5. This step tests the TR switch wiring for an open or the lack of the signal voltage from the PCM.
3. 6. This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
4. 7. This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
5. 8. This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
6. 9. This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.

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The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step tests for a faulty tow/haul switch.
2. 3. This step tests for voltage input from the BCM to the tow/haul switch.
3. 6. This step tests for ground integrity.

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Transmission Abbreviations

A/C: Air Conditioning

AC: Alternating Current

AT: Automatic Transmission

CCDIC: Climate Control Driver Information Center

DC: Direct Current

DIC: Driver Information Center

DLC: Diagnostic Link Connector

DMM: Digital Multimeter

DTC: Diagnostic Trouble Code

ECT: Engine Coolant Temperature

EMI: Electromagnetic Interference

IAT: Intake Air Temperature

IGN: Ignition

MAP: Manifold Absolute Pressure

MIL: Malfunction Indicator Lamp

NC: Normally Closed

NO: Normally Open

OBD: On Board Diagnostic

OSS: Output (Shaft) Speed Sensor

PC: Pressure Control

PCM: Powertrain Control Module

PWM: Pulse Width Modulation

RPM: Revolutions Per Minute

SS: Shift Solenoid

TAP: Transmission Adaptive Pressure

TCC: Torque Converter Clutch

TFP: Transmission Fluid Pressure

TFT: Transmission Fluid Temperature

TP: Throttle Position

TV: Throttle Valve

VSS: Vehicle Speed Sensor

WOT: Wide Open Throttle

4WD: Four-Wheel Drive

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Transmission Component and System Description

The mechanical components of the 4L60-E are as follows

1. Torque converter assembly
2. Servo assembly and 2-4 band assembly
3. Reverse input clutch and housing
4. Overrun clutch
5. Forward clutch
6. 3-4 clutch
7. Forward sprag clutch assembly
8. Lo and reverse roller clutch assembly
9. Lo and reverse clutch assembly
10. Two planetary gear sets: Input and Reaction
11. Oil pump assembly
12. Control valve body assembly

The electrical components of the 4L60-E are as follows

1. 1-2 and 2-3 shift solenoid valves
2. 3-2 shift solenoid valve assembly
3. Transmission pressure control (PC) solenoid
4. Torque converter clutch (TCC) solenoid valve
5. TCC pulse width modulation (PWM) solenoid valve
6. Automatic transmission fluid pressure (TFP) manual valve position switch
7. Automatic transmission fluid temperature (TFT) sensor
8. Vehicle speed sensor assembly

For more information, refer to Electronic Component Description .