Comprehensive Component Monitor - Transmission
General
The MIL is illuminated for all emissions related electrical component malfunctions. For malfunctions attributable to a mechanical component (such as a clutch, gear, band, valve, etc.), some transmissions are capable of not commanding the mechanically failed component and providing the remaining maximum functionality (functionality is reassessed on each power up)- in such case a non-MIL Diagnostic Trouble Code (DTC) will be stored and, if so equipped, a Transmission Control Indicator Light (TCIL) will flash.
Transmission Inputs
TRANSMISSION RANGE SENSOR CHECK OPERATION
| DTCs | P0705 invalid pattern for digital TRS P0706 Out of range signal frequency for PWM TRS P0707 Signal out of range low for PWM TRS P0708 Open circuit for digital TRS or signal out of range high for PWM TRS |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | Up to 30 seconds for pattern recognition, 5 seconds for analog faults |
TYPICAL TRS CHECK ENTRY CONDITIONS
| Auto Transmission Entry Conditions | Minimum | Maximum |
| Gear selector position | each position for up to 30 seconds | 480 seconds |
TYPICAL TRS MALFUNCTION THRESHOLDS
| Digital TRS:
Invalid pattern from 3 or 5 digital inputs and/or 1 analog circuit open for 5 seconds 4-bit digital TRS: Invalid pattern for 200 ms Analog TRS: Voltage > 4.8 volts or < 0.2 volts for 5 seconds Dual analog TRS: Voltage > 4.84 volts or < 0.127 volts for 200 ms or Sum of both inputs is outside the range of 5.0 volts +/- 0.29 volts for 200 ms PWM TRS: Frequency > 175 Hz or < 100 Hz, Duty Cycle > 90% or < 10% |
Most vehicle applications no longer have a standalone vehicle speed sensor input. The PCM sometimes obtains vehicle speed information from another module on the vehicle, i.e. ABS module. In most cases, however, vehicle speed is calculated in the PCM by using the transmission output shaft speed sensor signal and applying a conversion factor for axle ratio and tire programmed into the Vehicle ID block. A Vehicle Speed Output pin on the PCM provides the rest of the vehicle with the standard 8, 000 pulses/mile signal.
NOTE:
If the Vehicle ID block has not been programmed or has been programmed with an out-of-range (uncertified) tire/axle ratio, a P1639 DTC will be stored and the MIL will be illuminated immediately.
VEHICLE SPEED SENSOR FUNCTIONAL CHECK OPERATION
| DTCs | P0500 - VSS Circuit |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | 30 seconds |
TYPICAL VSS FUNCTIONAL CHECK ENTRY CONDITIONS
| Auto Transmission Entry Conditions | Minimum | Maximum |
| Gear selector position | drive | |
| Engine rpm (above converter stall speed) OR | 3000 rpm | |
| Turbine shaft rpm (if available) OR | 1500 rpm | |
| Output shaft rpm | 650 rpm | |
| Vehicle speed (if available) | 15 mph | |
| Manual Transmission Entry Conditions | Minimum | Maximum |
| Engine load | 50% | |
| Engine rpm | 2400 rpm |
TYPICAL VSS FUNCTIONAL CHECK MALFUNCTION THRESHOLDS
| Vehicle is inferred to be moving with positive driving torque and VSS is < 1 - 5 mph for 5 seconds |
OUTPUT SHAFT SPEED SENSOR FUNCTIONAL CHECK OPERATION
| DTCs | P0720 - OSS circuit P0721 - OSS range/performance -F-21, 6HP26 P0722 - OSS no signal P0723 - OSS intermittent/erratic - 6HP26 |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | TSS, Wheel Speed |
| Monitoring Duration | 30 seconds |
TYPICAL OSS FUNCTIONAL CHECK ENTRY CONDITIONS
| Auto Transmission Entry Conditions | Minimum | Maximum |
| Gear selector position | drive | |
| Engine rpm (above converter stall speed) OR | 3000 rpm | |
| Primary Pulley Speed (CFT30) OR | 400 rpm | |
| Turbine shaft rpm (if available) OR | 1500 rpm | |
| Output shaft rpm | 300 - 650 rpm | |
| Vehicle Speed (if available) | 12.5 - 15 mph |
TYPICAL OSS FUNCTIONAL CHECK MALFUNCTION THRESHOLDS
| Circuit/no signal - vehicle is inferred to be moving with positive driving torque and OSS < 100 to 200 rpm for 5 to 30 seconds 6HP26 Circuit/no signal: open or short circuit for > 0.6 seconds 6HP Range/Performance: > 200 rpm difference between OSS and wheel speed and > 250 rpm difference between OSS and input shaft speed F21 Range/Performance: TSS, ABS wheel speed and engine rpm correlate properly, but OSS error is greater than 15% for 10 seconds CFT30 Range/Performance: ABS wheel speed indicates a 6.24 mph difference with OSS calculated wheel speed 6HP26 Intermittent/Erratic: > -1000 rpm instantaneous change with locked torque converter clutch CFT30 Intermittent/Erratic: > 6000 rpm/sec change |
INTERMEDIATE SHAFT SPEED SENSOR FUNCTIONAL CHECK OPERATION
| DTCs | P0791 - ISS circuit |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | 30 seconds |
TYPICAL ISS FUNCTIONAL CHECK ENTRY CONDITIONS
| Auto Transmission Entry Conditions | Minimum | Maximum |
| Gear selector position | drive | |
| Engine rpm (above converter stall speed) OR | 3000 rpm | |
| Turbine shaft rpm (if available) OR | 1500 rpm | |
| Output shaft rpm | 650 rpm | |
| Vehicle speed (if available) | 15 mph |
TYPICAL ISS FUNCTIONAL CHECK MALFUNCTION THRESHOLDS
| Vehicle is inferred to be moving with positive driving torque and ISS < 250 rpm for 5 seconds |
TURBINE SHAFT SPEED SENSOR FUNCTIONAL CHECK OPERATION
| DTCs | P0715 - TSS circuit/ no signal P0718 - TSS erratic signal |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | OSS, Wheel Speed |
| Monitoring Duration | 30 seconds |
TYPICAL TSS FUNCTIONAL CHECK MALFUNCTION THRESHOLDS
| Circuit/no signal - vehicle is inferred to be moving with positive driving torque and TSS < 200 rpm for 5 - 30 seconds Erratic signal - observe 200 turbine speed spikes > 400 rpm with no more than 1.5 seconds between spikes |
TRANSMISSION FLUID TEMPERATURE SENSOR FUNCTIONAL CHECK OPERATION
| DTCs | P0711 - in range failure P0712 - short to ground P0713 - open circuit |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | ECT substituted if TFT has malfunction TFT inferred from pressure solenoid on CFT30 |
| Monitoring Duration | 5 seconds for electrical, 600 seconds for functional check |
TYPICAL TFT STUCK LOW/HIGH CHECK ENTRY CONDITIONS
| Auto Transmission Entry Conditions | Minimum | Maximum |
| Engine Coolant Temp (hot or cold, not midrange) | > 100 °F | < 20 °F |
| Time in Run Mode | 500 - 600 seconds | |
| Time in gear, Vehicle moving, Positive torque | 150 seconds | |
| Vehicle Speed | 15 mph | |
| Time with engine off (cold start) OR | 420 min | |
| Engine Coolant Temp AND Trans Fluid Temp (inferred cold start) | 122 °F |
TYPICAL TFT MALFUNCTION THRESHOLDS
| Opens/shorts:
TFT voltage <0.05 or > 4.6 volts for 5 - 12 seconds TFT Stuck low/high, i.e. TFT stuck at high temperature or stuck at low temperature): Stores a fault code if TFT stabilizes (stops increasing if temperature < 70 deg F, stops decreasing if temperature > 225 deg F) before reaching the temperature region where all MIL tests are enabled (70 to 225 deg F). If TFT remains constant (+/- 2 deg F) for approximately 2.5 minutes of vehicle driving outside the 70 to 225 deg F zone a P0711 fault code will be stored. Old logic used to indicate a "pass" for a single delta, and not test until the normal operating region (70-225 deg F) was reached. |
Shift Solenoid Check Operation
| DTCs | SS A P0750 - open circuit P0751 - functionally failed off P0752 - functionally failed on P0973 - short to ground P0974 - shorts to power P1714 ISIG functional (4R70 only, replaces P0751, P0752) SS B P0755 - open circuit P0756 - functionally failed off P0757 - functionally failed on P0976 - short to ground P0977 - shorts to power P1715 ISIG functional (4R70 only, replaces P0756, P0757) SS C P0760 - open circuit P0761 - functionally failed off P0762 - functionally failed on P0979 - short to ground P0980 - shorts to power SS D P0765 - open circuit P0766 - functionally failed off P0767 - functionally failed on P0982 - short to ground P0983 - shorts to power SS E P0770 - open circuit P0771 - functionally failed off P0772 - functionally failed on P0985 - short to ground P0986 - shorts to power |
| Monitor execution | electrical - continuous, functional - during off to on solenoid transitions |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | 0.5 to 5 seconds for electrical checks, 10 solenoid events for functional check |
TYPICAL SHIFT SOLENOID ISIG FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Transmission Fluid Temp | 70 °F | 225 °F |
| Throttle Position | positive drive torque (actual TP varies) |
TYPICAL SHIFT SOLENOID MECHANICAL FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Conditions (with turbine speed) | Minimum | Maximum |
| Gear ratio calculated | each gear | |
| Throttle position | positive drive torque |
TYPICAL SHIFT SOLENOID MECHANICAL FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Conditions (without turbine speed) | Minimum | Maximum |
| Gear ratio calculated | each shift | |
| Throttle position | positive drive torque |
TYPICAL SHIFT SOLENOID MALFUNCTION THRESHOLDS
| Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 - 5.0 seconds Electrical current check: Feedback current out of range for 0.5 seconds ISIG functional check: ISIG chip hardware circuit does not detect characteristic current dip and rise produced by solenoid movement. Mechanical functional check: Actual obtained gear or shift pattern indicates which shift solenoid is stuck on or off. |
GEAR RATIO CHECK OPERATION
| DTCs | P0731 incorrect gear 1 ratio P0732 incorrect gear 2 ratio P0733 incorrect gear 3 ratio P0734 incorrect gear 4 ratio P0735 incorrect gear 5 ratio P0729 incorrect gear 6 ratio P0736 incorrect reverse ratio |
| Monitor Execution | Continuous, in each gear |
| Monitor Sequence | None |
| Sensors OK | TSS, OSS, wheel speed |
| Monitoring Duration | 12 seconds |
TYPICAL FORWARD GEAR RATIO CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Gear selector position | forward range, > 8 seconds |
|
| Engine Torque | 100 NM | |
| Throttle position | 10% | |
| Not shifting | > 0.5 seconds | |
| Engine/input Speed | 550 rpm | |
| Output Shaft Speed | 250 rpm | 1350 rpm |
TYPICAL NEUTRAL GEAR RATIO CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Gear selector position | forward range, > 1 seconds |
|
| Absolute value of Engine rpm - turbine rpm | 150 rpm | |
| Output shaft speed | 250 rpm | 1350 rpm |
TYPICAL GEAR RATIO MALFUNCTION THRESHOLDS
| Forward gear check: > 30 error in commanded ratio for > 1.8 seconds that repeats 3 times |
TORQUE CONVERTER CLUTCH CHECK OPERATION
| DTCs | P0740 - open circuit P0742 - short to ground P0744 - short to power P0741 - functionally stuck off P2758 - functionally stuck on P1740 - Inductive signature (4R70 only, replaces P0741 / P2758) |
| Monitor Execution | electrical - continuous, mechanical - during lockup |
| Monitor Sequence | None |
| Sensors OK | TSS, OSS |
| Monitoring Duration | Electrical - 5 seconds, Functional - 5 lock-up events |
TYPICAL TCC ISIG FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Transmission Fluid Temp | 70 °F | 225 °F |
| Engine Torque | positive drive torque | |
| Commanded TCC duty cycle for 0 rpm slip | 60% | 90% |
TYPICAL TCC MECHANICAL FUNCTIONAL CHECK STUCK OFF ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Throttle Position | steady | |
| Engine Torque | positive drive torque | |
| Transmission Fluid Temp | 70 °F | 225 °F |
| Commanded TCC duty cycle (0 rpm slip) | 60% | 100% |
| Not Shifting |
TYPICAL TCC MALFUNCTION THRESHOLDS
| Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 - 5.0 seconds Electrical current check: Feedback current out of range for 0.5 seconds ISIG functional check: ISIG chip hardware circuit does not detect characteristic current dip and rise produced by solenoid movement. Mechanical check, stuck off: Slip across torque converter > 100 - 200 rpm or speed ratio < 0.93 Mechanical check, stuck on: Slip across torque converter < 20 rpm with converter commanded off Mechanical check, stuck on: engine rpm < 100 after drive engagement (engine stall) |
PRESSURE CONTROL SOLENOID CHECK OPERATION
| DTCs | P0960 - open circuit P0960 - short to ground P0963 - short to power |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | Electrical: 5 seconds, Mechanical functional: up to 30 seconds |
TYPICAL PRESSURE CONTROL SOLENOID MECHANICAL FUNCTIONAL CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Gear ratio calculated | each gear | |
| Transmission Fluid Temperature | 70 °F | 225 °F |
| Throttle Position | positive drive torque |
TYPICAL PRESSURE CONTROL SOLENOID MALFUNCTION THRESHOLDS
| Electrical circuit check: Output driver feedback circuit does not match commanded driver state for 0.5 - 5.0 seconds Electrical current check: Feedback current out of range for 0.5 seconds Mechanical functional check: Actual obtained gear pattern indicates Pressure Control solenoid fault |
INDUCTIVE SIGNATURE CHIP COMMUNICATION CHECK OPERATION
| DTCs | P1636 ISIG chip loss of communication |
| Monitor Execution | off-to-on solenoid transitions |
| Monitor Sequence | None |
| Sensors OK | |
| Monitoring Duration | < 100 solenoid events |
TYPICAL INDUCTIVE SIGNATURE CHIP COMMUNICATION CHECK ENTRY CONDITIONS
| Entry Conditions | Minimum | Maximum |
| Transmission Fluid Temp | 70 °F | 225 °F |
| Solenoid commanded off duration | < 2 seconds |
TYPICAL INDUCTIVE SIGNATURE COMMUNICATION CHIP MALFUNCTION THRESHOLDS
| Checksum error, chip not responding |