Symptoms - Automatic Transmission
| Diagnostic Category | Diagnostic Information |
|---|---|
| The following table consists of eight diagnostic categories that are located in the left-hand column. Using this column, choose the appropriate category based on the operating conditions of the vehicle or transmission. After selecting a category, use the right-hand column to locate the specific symptom diagnostic information. | |
| Fluid Diagnosis: This category contains the following topics: Fluid condition - appearance, contaminants, smell, overheating Line pressure - high or low Fluid leaks | Refer to Transmission Fluid Checking Procedure . Refer to Fluid Foaming . Refer to Transmission Overheats . Refer to Transmission Overheats at WOT . Refer to High Line Pressure . Refer to Low Line Pressure . Refer to Inadequate Lubrication at Low Line or Heavy Loads . Refer to Inadequate Lubrication . Refer to Fluid Leak Diagnosis . Refer to Case Extension Bearing/Seal Failed . Refer to Oil Out the Vent Tube . Refer to Automatic Transmission Fluid Leaks . |
| Noise and Vibration Diagnosis: This category contains the following topics: Noise - drive gear, final drive, whine, growl, rattle, buzz, popping Vibration | Refer to Noise . Refer to Vibration . Refer to Flexplate/Torque Converter Vibration Test . |
| Range Performance Diagnosis: This category contains the following topics: Drives in Neutral No Park/Neutral No Reverse Engine stalling No Drive No engine braking No or incorrect gear selection Shift selector indicator does not match transmission gear range | Refer to Forward Motion in Neutral . Refer to No Park . Refer to No Reverse . Refer to Engine Stall . Refer to No Torque in Reverse and Third . Refer to Loss of Power . Refer to No Torque in Second Gear . Refer to Loss of Drive . Refer to No Overrun Braking - D1 . Refer to No Engine Braking - D1 . Refer to No Overrun Braking - D2 . Refer to No Engine Braking - D2 . Refer to No Second Gear Engine Braking - D2 . Refer to No Overrun Braking - D3 . Refer to No Engine Braking - D3 . Refer to Engine Starts in Gear . Refer to Shift Lever Indicates Wrong Gear . Refer to No Gear Selection . Refer to Remains in Park . Refer to Difficult to Shift Out of Park . Refer to Does Not Stay in Park . Refer to Range Selector Displays Incorrect Range . |
| Shift Quality - Feel - Diagnosis: This category contains the following topics: Erratic shifts Harsh, soft, delayed or slipping shifts Harsh, soft, or delayed engagement | Refer to Erratic Shift Quality . Refer to Harsh Shifts . Refer to Transmission Slips . Refer to Harsh Shift 3 to 4 . Refer to Harsh Shift 4 to 3 . Refer to Harsh Shift D4 to D3, D2, or D1 . Refer to Soft Shifts . Refer to Delayed Shift 1 to 2 . Refer to Soft Shift 2 to 3 . Refer to Soft Shift D3 to D2 . Refer to Soft Shift 3 to 2 . Refer to No D3 to D2 . Refer to No D2 to D1 . Refer to Harsh Shift D to R . Refer to Soft Shift into R . Refer to Soft Shift R to D . |
| Shift Pattern: This category contains the following topics: One forward gear missing or slipping One forward gear only Two forward gears only Non-First gear start | Refer to No First Gear - D1 . Refer to No First Gear - D2 . Refer to No First Gear - D4 . Refer to No Second Gear - D1 . Refer to No Second Gear - D2 . Refer to No Second Gear - D4 . Refer to No Second Gear - D3 . Refer to No Third Gear - D3 . Refer to No Third Gear - D4 . Refer to No Fourth Gear - D4 . Refer to First Gear Only - D4 . Refer to Second Gear Only - D4 . Refer to First and Second Gear Only - D4 . Refer to First and Fourth Gear Only - D4 . Refer to Second and Third Gear Only - D4 . Refer to Third and Fourth Gear Only - D4 . Refer to Second Gear Starts . Refer to Third Gear Starts . Refer to Fourth Gear Starts . |
| Shift Speed Diagnosis: This category contains the following topic: Inaccurate or inconsistent shift points | Refer to Inaccurate Shift Points . |
| Torque Converter Diagnosis: This category contains the following topics: Torque Converter Diagnosis TCC does not apply TCC does not release TCC apply/release quality Poor acceleration/No torque multiplication Converter Ballooning Engine Stall | Refer to Torque Converter Diagnosis Procedure . Refer to Flexplate/Torque Converter Vibration Test . Refer to No Torque Converter Clutch (TCC) Apply . Refer to Torque Converter Clutch (TCC) Stuck On . Refer to Soft Torque Converter Clutch (TCC) Apply . Refer to Incorrect Torque Converter Clutch (TCC) Apply or Release . Refer to No Torque Multiplication . Refer to Torque Converter Clutch (TCC) Slipping . Refer to Converter Ballooning . Refer to Engine Stall in Neutral . |
| Symptom not found or no symptom detected | Refer to Transmission Fluid Checking Procedure . Refer to Road Test Procedure . Refer to Line Pressure Check Procedure . |
Symptoms - Automatic Transmission
Scheme 188
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 4: By disconnecting the TR switch, the ground path of all TR switch circuits would be removed and the PCM should recognize all circuits as open. The scan tool should display HI for all range signal states.
- 6: This step tests the TR switch wiring for an open or the lack of the signal voltage from the PCM.
- 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.
- 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.
- 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.
- 10: 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.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Install a scan tool. Turn ON the ignition, with the engine OFF. Select the TR Sw. on the scan tool. With the scan tool, observe the TR Sw. display while selecting each transmission range: P, R, N, D4, D3, D2 and D1. Does each selected transmission range match the scan tool TR Sw. display? | Go to Step 2 | Go to Step 3 | |
| 2 | Observe the IPC gear range display while selecting each transmission range: P, R, N, D4, D3, D2, D1. Does each selected transmission range match the IPC display? | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L | Go to Step 13 | |
| 3 | With the scan tool, observe the TR Sw. A/B/C/P display. Does the scan tool TR Sw. A/B/C/P parameter indicate HI for all range signal states? | Go to Step 15 | Go to Step 4 | |
| 4 | Turn OFF the ignition. Disconnect the TR switch connector. Turn ON the ignition, with the engine OFF. Does the scan tool TR Sw. A/B/C/P parameter indicate HI for all range signal states? | Go to Step 6 | Go to Step 5 | |
| 5 | Disconnect the IPC connector. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages and Console. Did the affected circuit display HI? | Go to Step 18 | Go to Step 6 | |
| 6 | Using the DMM and the J 35616 GM Terminal Test Kit, measure the voltage from terminal 5 of the TR switch connector to ground. Measure the voltage from terminal 6 of the TR switch connector to ground. Measure the voltage from terminal 8 of the TR switch connector to ground. Measure the voltage from terminal 4 of the TR switch connector to ground. Does the voltage measure within the specified value at all four terminals? | 10-12 V | Go to Step 7 | Go to Step 12 |
| 7 | Connect a fused jumper wire from terminal 5 of the TR switch connector, signal circuit A, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit A is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 8 | |
| 8 | Connect a fused jumper wire from terminal 4 of the TR switch connector, signal circuit B, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit B is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 9 | |
| 9 | Connect a fused jumper wire from terminal 6 of the TR switch connector, signal circuit C, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit C is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 10 | |
| 10 | Connect a fused jumper wire from terminal 8 of the TR switch connector, signal circuit P, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit P is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 13 | |
| 11 | Test the signal circuits of the TR switch that did not indicate HI for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 17 | |
| 12 | Test the signal circuits of the TR switch and the PCM that did not indicate proper voltage for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 17 | |
| 13 | Test the signal circuits of the TR switch between the PCM and the IPC for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 18 | |
| 14 | Test the affected signal circuits of the TR switch for a shorted together condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 16 | |
| 15 | Test the ground circuit of the TR switch for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 16 | |
| 16 | Replace the TR switch. The TR switch is part of the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement . Did you complete the replacement? | Go to Step 19 | ||
| 17 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L. Did you complete the replacement? | Go to Step 19 | ||
| 18 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages and Console. Did you complete the replacement? | Go to Step 19 | ||
| 19 | Turn ON the ignition, with the engine OFF. With the scan tool, observe the TR Sw. display while selecting each transmission range: P, R, N, D4, D3, D2 and D1. Does each selected transmission range match the scan tool TR Sw. display? | System OK | Go to Step 2 |
Range Selector Displays Incorrect Range
Scheme 189
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step tests for a faulty tow/haul switch.
- 3: This step tests for voltage input from the BCM to the tow/haul switch.
- 6: This step tests for ground integrity.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Install a scan tool. Turn ON the ignition, with the engine OFF. Cycle the tow/haul switch while observing Tow/Haul Mode on the scan tool. Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again? | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L | Go to Step 2 |
| 2 | Remove the connector from the tow/haul switch. Using the J 35616 GM Terminal Test Kit, install a fused jumper wire from terminal D to terminal A of the tow/haul switch connector. Does the scan tool Tow/Haul Mode indicate a status change? | Go to Step 7 | Go to Step 3 |
| 3 | Using the DMM and the J 35616 , measure the voltage at terminal D of the tow/haul switch connector. Is ignition voltage measured? | Go to Step 6 | Go to Step 4 |
| 4 | Using the DMM and the J 35616 , measure the voltage at terminal C3-B11 of the body control module (BCM). Is ignition voltage measured? | Go to Step 5 | Go to Step 8 |
| 5 | Test the Tow/Haul switch signal circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L |
| 6 | Test the ground circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L |
| 7 | Replace the tow/haul switch. Refer to Trim Plate Bezel Replacement - Instrument Panel (I/P) Cluster in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 9 | |
| 8 | Test the BCM for proper operation. Refer to Diagnostic Starting Point - Body Control System in Body Control System. Did you find and correct the condition? | Go to Step 9 | |
| 9 | After the repair is complete, observe Tow/Haul Mode on the scan tool display, while cycling the tow/haul switch. Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again? | System OK | Go to Step 1 |
Tow/Haul Switch/Indicator Always On or Inoperative