Diagnostic Starting Point - Automatic Transmission
Begin the system diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check - Vehicle in Vehicle DTC Information will provide the following information
- The identification of the control modules which command the system
- The ability of the control modules to communicate through the serial data circuit
- The identification of any stored diagnostic trouble codes (DTCs) and their status
The use of the Diagnostic System Check - Vehicle in Vehicle DTC Information will identify the correct procedure for diagnosing the system and where the procedure is located.
Scan Tool Output Controls
| Scan Tool Output Control | Additional Menu Selection(s) | Description |
|---|---|---|
| 1-2 Solenoid | The TCM commands the 1-2 shift solenoid valve ON and OFF. The scan tool 1-2 Sol. parameter should match the commanded state. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to Shift Solenoid Valve State and Gear Ratio . When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. When the engine is running, the following control limits apply: Only sequential gear changes are allowed. For example, 1st to 3rd is not allowed. If a non-sequential gear change is attempted, the message "Non-sequential gear changes not allowed. Gear changes must be in order" appears on the scan tool display. The vehicle speed must be below a calibrated value. If the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The engine speed must be below a calibrated value. If the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. Downshifts are allowed only when the vehicle speed is below a calibrated value. If the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1 downshift" appears on the scan tool display. The gear requested may not be greater than the current selected transmission range. For example, 3rd gear is not allowed if the transmission range is D2. If the gear requested is greater than the current selected transmission range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. | |
| 2-3 Solenoid | The TCM commands the 2-3 shift solenoid valve ON and OFF. The scan tool 2-3 Sol. parameter should match the commanded state. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to Shift Solenoid Valve State and Gear Ratio . When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid will remain ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. When the engine is running, the following control limits apply: Only sequential gear changes are allowed. For example, 1st to 3rd is not allowed. If a non-sequential gear change is attempted, the message "Non-sequential gear changes not allowed. Gear changes must be in order" appears on the scan tool display. The vehicle speed must be below a calibrated value. If the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The engine speed must be below a calibrated value. If the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. Downshifts are allowed only when the vehicle speed is below a calibrated value. If the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1 downshift" appears on the scan tool display. The gear requested may not be greater than the current selected transmission range. For example, 3rd gear is not allowed if the transmission range is D2. If the gear requested is greater than the current selected transmission range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. | |
| 4-5 Solenoid | The TCM commands the 4-5 shift solenoid valve ON and OFF. The scan tool 4-5 Sol. parameter should match the commanded state. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to Shift Solenoid Valve State and Gear Ratio . When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid will remain ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. When the engine is running, the following control limits apply: Only sequential gear changes are allowed. For example, 1st to 3rd is not allowed. If a non-sequential gear change is attempted, the message "Non-sequential gear changes not allowed. Gear changes must be in order" appears on the scan tool display. The vehicle speed must be below a calibrated value. If the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The engine speed must be below a calibrated value. If the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. Downshifts are allowed only when the vehicle speed is below a calibrated value. If the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1 downshift" appears on the scan tool display. The gear requested may not be greater than the current selected transmission range. For example, 3rd gear is not allowed if the transmission range is D2. If the gear requested is greater than the current selected transmission range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. | |
| Reset Transmission Adapts | The TCM clears, or resets, all TAP cells to zero. There are no limits to using this control. It may be performed with the engine running or when the ignition is ON, and the engine is OFF. | |
| Reset Transmission Oil Life | The TCM resets the amount of oil life remaining to 100 percent. There are no limits to using this output control. It may be performed with the engine running or when the ignition is ON, and the engine is OFF. | |
| PC Solenoid | The TCM commands the amperage to the pressure control solenoid in order to control transmission line pressure. As the amperage increases, the line pressure decreases. As the amperage decreases, the line pressure increases. The amperage range is 0.10-1.10 and may be commanded in one-tenth amp increments. When the ignition is ON, and the engine is OFF, the reference, commanded, amperage may be controlled within calibrated limits. The scan tool parameter "PC Sol. Ref. Current" changes, but the parameter "PC Sol. Actual Current" does not change. The reference current remains until commanded otherwise. When the engine is running, the following control limits apply: When the transmission range is Park or Neutral, the reference, commanded, amperage may be controlled within calibrated limits. The engine speed must be less than 1,500 RPM. If the engine speed is greater than 1,500 RPM, the message "TR in park/neutral and engine speed over 1,500 RPM" appears on the scan tool display. Both the scan tool parameters "PC Sol. Ref. Current" and "PC Sol. Actual Current" change. Both current readings remain until commanded otherwise. When the transmission range is not in Park or Neutral, the reference amperage can only be controlled less than the current determined by the TCM. The TCM does not allow a value to be selected that may cause damage to the transmission. If the requested amperage is more than allowed by the TCM, the message "Requested current for the PC Solenoid is too high" appears on the scan tool display. Transmission IMS DTCs must not be active. If a transmission IMS DTC is active, the message "Engine running with transmission DTC present" appears on the scan tool display. | |
| Shift Transmission | The TCM commands upshifts and downshifts. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to Shift Solenoid Valve State and Gear Ratio . When the ignition is ON, and the engine is OFF, there are no limits to this control. The scan tool shift solenoid states change to match the Commanded Gear selected. When the engine is running, the following control limits apply: The TCM does not allow a shift if it causes the engine RPM to exceed a calibrated limit. If a gear is requested and the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. The TCM does not allow a 3-2 or 2-1 downshift if the vehicle speed exceeds a calibrated limit. If either downshift is requested and the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1 downshift" appears on the scan tool display. The TCM does not allow a 4-3 downshift if the vehicle speed exceeds a calibrated limit. If a 4-3 downshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The TCM does not allow an upshift if the vehicle speed exceeds a calibrated limit. If an upshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The TCM does not allow an upshift that is greater than the current selected transmission range. For example 3rd gear is not allowed if the transmission range is D2. If an upshift is requested that is greater than the current selected transmission range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display. | |
| TCC Control Solenoid | The TCM commands the duty cycle of the TCC PWM solenoid. The duty cycle is represented by a percentage of ON, energized, time. Approximately 90-100 percent duty cycle represents an ON, energized, commanded state. Zero percent represents an OFF, non-energized, commanded state. The scan tool TCC Duty Cycle parameter should match the commanded state. When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON, 90-100 percent duty cycle until commanded OFF, zero percent duty cycle, and vice versa. When the output control is exited, the solenoid duty cycle is determined by the TCM. When the engine is running, the following control limits apply: If the transmission range is Park, and the transmission is in hot mode, the TCC control solenoid may not be commanded OFF. If the solenoid is requested OFF, the message "TCC OFF command disabled in Hot Mode" appears on the scan tool display. The TCC control solenoid may not be commanded OFF for more than a calibrated amount of time. If the solenoid is commanded OFF, for a certain amount of time, the message "TCC OFF time has been exceeded" appears on the scan tool display. | |
| High Side Driver 1 | The TCM commands the driver for the solenoid voltage supply ON and OFF. When the ignition is ON, and the engine is OFF, there are no limits to this control. High side driver 1 may not be commanded ON and OFF with the scan tool if the engine is running. | |
| High Side Driver 2 | The TCM commands the driver for the solenoid voltage supply ON and OFF. When the ignition is ON, and the engine is OFF, there are no limits to this control. High side driver 2 may not be commanded ON and OFF with the scan tool if the engine is running. |
Scan Tool Output Controls
Scan Tool Data List
Use the Scan Tool Data List under the following conditions
- The «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) has been completed
- The On-Board Diagnostics are functioning properly
- No DTCs are present
| IMPORTANT | Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts. |
Only the parameters listed below are used in this service manual for diagnosing. If a scan tool displays other parameters, the values are not recommended by General Motors for use in diagnosis.
Scan tool values below were recorded under the following conditions
- Engine at idle
- Upper radiator hose is hot
- Closed throttle
- Transmission in PARK
- Closed loop operation
- Accessories OFF
- Brake pedal not applied
| Scan Tool Parameter | Data List* | Units Displayed | Typical Data Value |
|---|---|---|---|
| 1-2 Shift Error | F2, F7/F0 | Seconds | Varies |
| 1-2 Shift Time | F0, F2, F7/F0 | Seconds | Varies |
| 1-2 Sol. | F0, F2, F3, F4, F5 | On/Off | Off |
| 1-2 Sol. CKT Status | F2 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| 1-2 TAP Cell (4-16) | F7/F0 | KPa (psi) | Varies |
| 2-3 Shift Error | F3, F7/F1 | Seconds | Varies |
| 2-3 Shift Time | F0, F3, F7/F1 | Seconds | Varies |
| 2-3 Sol. | F0, F2, F3, F4, F5 | On/Off | On |
| 2-3 Sol. CKT Status | F3 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| 2-3 TAP Cell (4-16) | F7/F1 | KPa (psi) | Varies |
| 3-4 Shift Error | F4, F7/F2 | Seconds | Varies |
| 3-4 Shift Time | F0, F4, F7/F2 | Seconds | Varies |
| 3-4 TAP Cell (4-16) | F7/F2 | KPa (psi) | Varies |
| 4-5 Shift Error | F5, F7/F3 | Seconds | Varies |
| 4-5 Shift Time | F0, F5, F7/F3 | Seconds | Varies |
| 4-5 Sol. | F0, F2, F3, F4, F5 | On/Off | Off |
| 4-5 Sol. CKT Status | F5 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| 4-5 TAP Cell (4-16) | F7/F3 | KPa (psi) | Varies |
| A/C Clutch | F0 | On/Off | Off |
| Commanded Gear | F0, F1, F2, F3, F4, F5, F6 | 1,2,3,4,5 | 1 |
| Cruise | F0 | Enabled/Disabled | Disabled |
| Current TAP Cell | F7/F0, F7/F1, F7/F2, F7/F3 | 4-16 | Varies |
| Driver Shift Control | F0 | Active, Inactive | Inactive |
| Driver Shift Request | F0 | Upshift, Downshift, Invalid, None | None |
| ECT | F0, F1 | °C (°F) | 85-115°C (185-239°F) |
| Engine Speed | F0, F1, F2, F3, F4, F5, F6 | RPM | 650-800 RPM |
| Engine Torque | F0, F1 | N.m (lb ft) | 0-13 N.m (lb ft) |
| Gear Ratio | F0, F1, F2, F3, F4, F5 | Ratio | Varies |
| High Side Driver 1 | F6 | Enabled/Disabled | Enabled |
| High Side Driver 1 CKT Status | F6 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| High Side Driver 2 | F1, F2, F3, F4, F5 | Enabled/Disabled | Enabled |
| High Side Driver 2 CKT Status | F1, F2, F3, F4, F5 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| Ignition Voltage | F0 | Volts | 12.0-14.7 Volts |
| IMS A/B/C/P | F0 | HI/LOW | HIGH/LOW/LOW/HIGH |
| IMS | F0 | Park, Park/Reverse, Reverse, Reverse/Neutral, Neutral, Neutral/Drive 5, Drive 5, Drive 5/Drive 4, Drive 4, Drive 4/Drive 3, Drive 3, Drive 3/Drive 2, Drive 2, Invalid | Park |
| Last Shift Time | F0 | Seconds | Varies |
| PC Sol. Actual Current | F0, F6 | Amps | Varies |
| PC Solenoid Duty Cycle | F0, F6 | % | Varies |
| PC Sol. Ref. Current | F0, F6 | Amps | Varies |
| Steady State TAP 1 GR | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 1 GR/TCC | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 2 GR | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 2 GR/TCC | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 3 GR | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 3 GR/TCC | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 4 GR | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 4 GR/TCC | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 5 GR | F7/F4 | KPa (psi) | Varies |
| Steady State TAP 5 GR/TCC | F7/F4 | KPa (psi) | Varies |
| Steady State TAP Reverse | F7/F4 | KPa (psi) | Varies |
| TCC Brake Switch | F0, F1 | Open/Closed | Closed |
| TCC Duty Cycle | F0, F1 | % | 0% |
| TCC Duty Cycle CKT Status | F1 | OK/Short to Volts/Open/SHT GND/Indeterminate | OK |
| TCC Slip Speed | F0, F1 | RPM | 0 RPM |
| TP Angle | F0, F1, F2, F3, F4, F5, F6 | % | 0 |
| Traction Control | F0 | Active/Inactive | Inactive |
| Trans. Fluid Temp. | F0, F1, F6 | °C (°F) | 85-110°C (185-239°F) |
| Trans. Oil Life | F0 | 0-100% | Varies |
| Transmission Hot Mode | F0, F1 | On/Off | Off |
| Transmission ISS | F0, F1, F2, F3, F4, F5 | RPM | 650-800 RPM |
| Transmission OSS | F0, F1, F2, F3, F4, F5 | RPM | 0 RPM |
| *Data List Legend F0: Transmission Data F1: TCC Data F2: 1-2 Shift Data F3: 2-3 Shift Data F4: 3-4 Shift Data F5: 4-5 Shift Data F6: PC Solenoid Data F7/F0: Transmission Adapts/1-2 Adapt. Data F7/F1: Transmission Adapts/2-3 Adapt. Data F7/F2: Transmission Adapts/3-4 Adapt. Data F7/F3: Transmission Adapts/4-5 Adapt. Data F7/F4: Transmission Adapts/Steady State Data | |||
Scan Tool Data List
Scan Tool Data Definitions
This list explains each data message displayed on the scan tool. This information will assist you in tracking down emissions or driveability DTCs, because you can view the displays while you are driving the vehicle. Refer to Diagnostic System Check - Vehicle for additional information.
Diagnostic Trouble Code (DTC) Type Definitions
Diagnostic Trouble Codes (DTCs) are grouped into several types. Each type has a unique set of characteristics for MIL operation, DTC storage, and DTC clearing. The following list contains a brief summary of the DTC types and the associated properties of each.
Type A
This DTC is emissions related. The MIL illuminates and default actions, if any, are activated immediately after a failure is detected. The DTC is then stored in history and the Freeze Frame data is captured.
Type B
This DTC is emissions related. Default actions, if any, are activated and a Failure Record is stored after the first failure is detected. At the time of the first fail, the DTC will appear in memory as pending. If the next trip reports a pass, the pending DTC is deleted. If the failure recurs on the next consecutive drive cycle, the MIL illuminates, the DTC is stored in history, and the Freeze Frame data is captured at the time of failure.
Type C
This DTC is non emission related and does not turn on the MIL. When a Type C DTC sets, a message may be displayed on the driver information center. Type C DTCs that do not display a message were formerly referred to as type D DTCs.
Diagnostic Trouble Code (DTC) List/Type
Diagnostic Trouble Code (DTC) List/Type