Automatic Transmission - 5l40-e/5l50-e - (DTC p0757 to DTC p1833) Cadillac STS I

Scheme 60

Circuit Description

The 2-3 shift solenoid (SS) valve is a normally-closed exhaust valve that, in conjunction with the 1-2 SS valve, allows 4 different shifting combinations. The 2-3 SS valve is attached to the control valve body, within the transmission.

The transmission control module (TCM) monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0757 sets under two conditions

1. A stuck ON 2-3 SS valve
2. A stuck ON 2-3 shift valve

If the TCM detects a 1-2-2-1-1 shift pattern, then DTC P0757 sets. DTC P0757 is a type B DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0757 2-3 Shift Solenoid (SS) Valve Performance - No Third, Fourth or Fifth Gear

Conditions for Running the DTC

1. No TP sensor DTC P0120.
2. No ISS DTCs P0716 or P0717.
3. No OSS DTCs P0722 or P0723.
4. No TCC stuck ON DTC P0742.
5. No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
6. No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
7. No engine torque delivered signal DTC P2637.
8. The engine run time is greater than 5 seconds.
9. The IMS range is not PARK, NEUTRAL or REVERSE.
10. The transmission fluid temperature is 20-130°C (68-266°F).
11. The throttle position is greater than 10 percent.
12. The input shaft speed is 200-6,800 RPM.
13. The output shaft speed is greater than 100 RPM.

Conditions for Setting the DTC

Both of the following conditions must occur once during the same trip

1. The TCM commands 3rd gear when the output shaft speed is 200 RPM or greater, the engine torque is greater than 20 N.m (15 lb ft), and the resulting gear ratio is 2.16:1-2.27:1 for 2 seconds.
2. The TCM commands 4th or 5th gear when the engine torque is greater than 12 N.m (9 lb ft) and the resulting gear ratio is 3.33:1-3.50:1 for 2 seconds.

Action Taken When the DTC Sets

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM inhibits 4th and 5th gears.
5. The TCM inhibits TCC.
6. The TCM inhibits autograde braking.
7. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
8. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
9. The TCM stores DTC P0757 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the DTC

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

Diagnostic Aids

1. If you clear DTC P0757, and then cannot reset DTC P0757, the following conditions may exist: Fluid contamination Plugged fluid circuits Restricted fluid circuits
2. Refer to «Shift Solenoid Valve State and Gear Ratio»(/cadillac/sts/i-2004-2007/remont/automatic-trans/#automatic-transmission-5l40-e5l50-e-introduction-repair-instructions__shift-solenoid-valve-state-and-gear) .

Test Description

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

1. 3: This step verifies a 1-2-2-1-1 shift pattern.
2. 4: This step tests for a mechanical or hydraulic condition causing the 2-3 SS valve to be stuck ON, or the circuit to be released.

DTC P0757

Scheme 61

The 4-5 shift solenoid (SS) valve is a normally-closed exhaust valve. When the 1-2 and the 2-3 SS valves are both OFF, the 4-5 SS valve turns off to shift the transmission into 5th gear. When either of the other two shift solenoids are ON, the 4-5 SS allows powertrain braking. The 4-5 SS valve is attached to the control valve body, within the transmission.

The transmission control module (TCM) monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0761 sets under two conditions

1. A stuck OFF 4-5 SS valve
2. A stuck OFF 4-5 shift valve

If the TCM detects a 1-2-3-5-5 shift pattern, then DTC P0761 sets. DTC P0761 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0761 4-5 Shift Solenoid (SS) Valve Performance - No Fourth Gear

1. No TP sensor DTC P0120.
2. No ISS DTCs P0716 or P0717.
3. No OSS DTCs P0722 or P0723.
4. No TCC stuck ON DTC P0742.
5. No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
6. No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
7. No engine torque delivered signal DTC P2637.
8. The engine run time is greater than 5 seconds.
9. The IMS range is not PARK, NEUTRAL or REVERSE.
10. The transmission fluid temperature is 20-130°C (68-266°F).
11. The throttle position is greater than 10 percent.
12. The input shaft speed is 200-6,800 RPM.
13. The output shaft speed is greater than 100 RPM.
14. The engine torque is greater than 36 N.m (27 lb ft).

The TCM commands 4th gear and the resulting gear ratio is 0.73:1-0.77:1 for 4 seconds twice during the same trip.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM inhibits autograde braking.
5. The TCM inhibits powertrain braking.
6. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
7. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
8. The TCM stores DTC P0761 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

1. If you clear DTC P0761, and then cannot reset DTC P0761, the following conditions may exist: Fluid contamination Plugged fluid circuits Restricted fluid circuits
2. Refer to «Shift Solenoid Valve State and Gear Ratio»(/cadillac/sts/i-2004-2007/remont/automatic-trans/#automatic-transmission-5l40-e5l50-e-introduction-repair-instructions__shift-solenoid-valve-state-and-gear) .

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

1. 3: This step verifies a 1-2-3-5-5 shift pattern.
2. 4: This step tests for a mechanical or hydraulic condition causing the 4-5 SS valve to be stuck OFF, or the circuit to be applied.

DTC P0761

The 4-5 shift solenoid (SS) valve is a normally-closed exhaust valve. When the 1-2 and the 2-3 SS valves are both OFF, the 4-5 SS valve turns OFF to shift the transmission into 5th gear. When either of the other two shift solenoids are ON, the 4-5 SS turn OFF in order to enable powertrain braking. The 4-5 SS valve is attached to the control valve body, within the transmission.

The transmission control module (TCM) monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0762 sets under two conditions

1. A stuck ON 4-5 SS valve
2. A stuck ON 4-5 shift valve

If the TCM detects a 1-2-3-4-4 shift pattern, then DTC P0762 sets. DTC P0762 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0762 4-5 Shift Solenoid (SS) Valve Performance - No Fifth Gear

1. No TP sensor DTC P0120.
2. No ISS DTCs P0716 or P0717.
3. No OSS DTCs P0722 or P0723.
4. No TCC stuck ON DTC P0742.
5. No shift solenoid electrical DTCs P0973, P0974, P0976, P0977, P0979, or P0980.
6. No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
7. No engine torque delivered signal DTC P2637.
8. The engine run time is greater than 5 seconds.
9. The IMS range is not PARK, NEUTRAL or REVERSE.
10. The transmission fluid temperature is 20-130°C (68-266°F).
11. The throttle position is greater than 10 percent.
12. The input shaft speed is 200-6,800 RPM.
13. The output shaft speed is greater than 100 RPM.
14. The engine torque is greater than 36 N.m (27 lb ft).

The following conditions must occur twice during the same trip

1. The TCM has commanded either 2nd or 3rd gear for 3 seconds or greater.
2. The TCM commands 5th gear and the resulting gear ratio is 0.98:1-1.03:1 for 3.5 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM inhibits powertrain braking.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P0762 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

1. If you clear DTC P0762, and then cannot reset DTC P0762, the following conditions may exist: Fluid contamination Plugged fluid circuits Restricted fluid circuits
2. Refer to «Shift Solenoid Valve State and Gear Ratio»(/cadillac/sts/i-2004-2007/remont/automatic-trans/#automatic-transmission-5l40-e5l50-e-introduction-repair-instructions__shift-solenoid-valve-state-and-gear) .

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

1. 3: This step verifies a 1-2-3-4-4 shift pattern.
2. 4: This step tests for a mechanical or hydraulic condition causing the 4-5 SS valve to be stuck ON, or the circuit to be released.

DTC P0762

Scheme 62

The TAP Shift system allows the driver to manually shift gears by using the TAP Shift switches located on the automatic transmission shifter. Pushing the Up switch will command an upshift and pushing the Down switch will command a downshift. The TAP Shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.

If the transmission control module (TCM) detects the upshift circuit active for an extended period of time, DTC P0815 sets. DTC P0815 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P0815 Upshift Switch Circuit

1. No Tap up/Tap down DTC P0826.
2. No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
3. The engine run time is greater than 5 seconds.
4. The time since last gear selector range change is greater than 6 seconds.

The TCM detects an upshift request for 2 seconds in PARK or for 600 seconds.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM disables TAP shift operation.
3. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
4. The TCM stores DTC P0815 in TCM history.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

DTC P0815

The TAP Shift system allows the driver to manually shift gears by using the TAP Shift switches located on the automatic transmission shifter. Pushing the Up switch will command an upshift and pushing the Down switch will command a downshift. The TAP Shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.

If the transmission control module (TCM) detects the downshift circuit active for an extended period of time, then DTC P0816 sets. DTC P0816 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P0816 Downshift Switch Circuit

1. No Tap up/Tap down DTC P0826.
2. No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
3. The engine run time is greater than 5 seconds.
4. The time since last gear selector range change is greater than 6 seconds.

The TCM detects a downshift request for 2 seconds in PARK or for 600 seconds.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM disables TAP Shift operation.
3. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
4. The TCM stores DTC P0816 in TCM history.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

DTC P0816

The TAP Shift system allows the driver to manually shift gears by using the TAP Shift switches located on the automatic transmission shifter. Pushing the Up switch will command an upshift and pushing the Down switch will command a downshift. The TAP Shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.

If the transmission control module (TCM) detects an invalid voltage on the Up/Down Switch Circuit, DTC P0826 sets. DTC P0826 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P0826 Up and Down Shift Switch Circuit

The engine run time is greater than 5 seconds.

The TCM detects an invalid voltage on the TAP Up/Down Signal Circuit for 300 seconds.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM disables TAP Shift operation.
3. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
4. The TCM stores DTC P0826 in TCM history.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

DTC P0826

The engine control module (ECM) provides 12-volts to the park/neutral switch of the manual shift shaft position switch. The manual shift shaft position switch is a sliding contact assembly that attaches to the manual shift shaft inside the transmission. The switch consists of five separate circuits, four of which indicate gear selector position to the transmission control module (TCM), and one that indicates park/neutral position to the ECM. When the transmission is in Park or Neutral, the switch closes and pulls the ECM voltage low, 0 volts. When the transmission is not in Park or Neutral, the ECM voltage is high, 12 volts. The ECM uses the switch in order to enable starter operation.

If the Park/Neutral switch and the transmission manual shift shaft position switch do not agree for a specified length of time, DTC P0850 sets. DTC P0850 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P0850 Park/Neutral Position (PNP) Switch Circuit

The ignition is ON.

DTC P0850 sets when either of the following conditions are true

Condition 1

The park/neutral switch circuit is low, 0 volts, for 100 seconds while the TCM is reporting the gear selector is in REVERSE or any forward range.

Condition 2

The park/neutral switch circuit is high, 12 volts, for 200 seconds while the TCM is reporting the gear selector is in PARK or NEUTRAL.

1. The ECM does not illuminate the malfunction indicator lamp (MIL).
2. The ECM uses the transmission range data to enable engine cranking.
3. The ECM stores the operating conditions when the Conditions for Setting the DTC are met. This information is stored as a Failure Record.
4. The ECM stores DTC P0850 in ECM history.

Conditions for Clearing the MIL/DTC

1. The ECM clears the DTC from ECM history if the vehicle completes 40 warm-up cycles without a non emission diagnostic fault occurring.
2. The ECM cancels the default action when the ignition is OFF long enough in order to power down the ECM.
3. A scan tool can clear the DTC.

DTC P0850

Transmission fluid life is determined by monitoring transmission fluid temperature over a period of time. The transmission control module (TCM) calculates transmission fluid life based on a set of temperature ranges stored in TCM memory. As the vehicle is driven, a counter increments. The rate at which the counter increments depends on the temperature range in which the transmission is currently operating. The higher the temperature range, the faster the counter increments. As the counts increment, the TCM will begin to decrease the fluid life percentage from 100, high fluid life, to 0, low fluid life.

If the TCM detects a calculated transmission oil life of 10 percent or less, then DTC P0897 sets. DTC P0897 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P0897 Transmission Fluid Life

1. No Transmission Fluid Overtemperature DTC P0218.
2. No TFT DTCs P0711, P0712, or P0713.

The calculated transmission oil life remaining is less than 10 percent.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. CHANGE TRANSMISSION FLUID displays on the driver information center (DIC).
3. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
4. The PCM stores DTC P0897 in TCM history.

Conditions for Clearing the DIC/DTC

1. The TCM clears the DIC when the condition no longer exits.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Inspect the transmission cooling system for possible blockage and restrictions.

The number below refers to the step number on the diagnostic table.

1. 2: This step changes the AT fluid and filter. It is important to reset the oil life monitor after the fluid and filter are replaced.

DTC P0897

Scheme 63

The 1-2 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 1-2 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 1-2 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous open or short to ground in the 1-2 shift solenoid valve circuit, then DTC P0973 sets. DTC P0973 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0973 1-2 Shift Solenoid (SS) Control Circuit Low Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0973 sets when either of the following conditions occur for 4.3 seconds

1. The TCM detects an open in the 1-2 shift solenoid valve circuit when HSD2 is commanded ON.
2. The TCM detects a short to ground in the 1-2 shift solenoid valve circuit when HSD2 is commanded OFF.

1. Powertrain braking is disabled at the time that the TCM first detects the failure, before the DTC sets.
2. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
3. The TCM turns off power to all solenoids.
4. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
5. The TCM commands maximum line pressure.
6. The TCM freezes transmission adaptive functions.
7. Torque management is inhibited.
8. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
9. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
10. The TCM stores DTC P0973 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 5: Listen for an audible click when the solenoid energizes.

DTC P0973

The 1-2 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 1-2 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 1-2 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous short to voltage in the 1-2 shift solenoid valve circuit, then DTC P0974 sets. DTC P0974 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0974 1-2 Shift Solenoid (SS) Control Circuit High Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0974 sets when the TCM detects a short to voltage in the 1-2 shift solenoid valve circuit for 4.3 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM inhibits 3-2 downshifts if the vehicle speed is greater than 8 km/h (5 mph).
4. The TCM freezes transmission adaptive functions.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P0974 in TCM history.

DTC P1843 may set when a communication fault exists between the ECM and TCM. Inspect for DTC C0100. If this DTC is present, diagnose it first.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 2: Listen for an audible click when the solenoid energizes.

DTC P0974

The 2-3 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 2-3 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 2-3 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous open or short to ground in the 2-3 shift solenoid valve circuit, then DTC P0976 sets. DTC P0976 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0976 2-3 Shift Solenoid (SS) Control Circuit Low Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0976 sets when either of the following conditions occur for 4.3 seconds

1. The TCM detects an open in the 2-3 shift solenoid valve circuit when HSD2 is commanded ON.
2. The TCM detects a short to ground in the 2-3 shift solenoid valve circuit when HSD2 is commanded OFF.

1. Powertrain braking is disabled at the time that the TCM first detects the failure, before the DTC sets.
2. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
3. The TCM turns off power to all solenoids.
4. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
5. The TCM commands maximum line pressure.
6. The TCM freezes transmission adaptive functions.
7. Torque management is inhibited.
8. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
9. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
10. The TCM stores DTC P0976 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 2: Listen for an audible click when the solenoid energizes.

DTC P0976

The 2-3 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 2-3 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 2-3 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous short to voltage in the 2-3 Shift Solenoid valve circuit, then DTC P0977 sets. DTC P0977 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0977 2-3 Shift Solenoid (SS) Control Circuit High Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0976 sets when the TCM detects a short to voltage in the 2-3 shift solenoid valve circuit for 4.3 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM inhibits first gear.
4. The TCM freezes transmission adaptive functions.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P0976 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 2: Listen for an audible click when the solenoid energizes.

DTC P0977

The 4-5 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 4-5 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 4-5 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous open or short to ground in the 4-5 shift solenoid valve circuit, then DTC P0979 sets. DTC P0979 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0979 4-5 Shift Solenoid (SS) Control Circuit Low Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0979 sets when one of the following conditions occur for 4.3 seconds

1. The TCM detects an open in the 4-5 shift solenoid valve circuit when HSD2 is commanded ON.
2. The TCM detects a short to ground in the 4-5 shift solenoid valve circuit when HSD2 is commanded OFF.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
2. The TCM turns off power to all solenoids.
3. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
4. The TCM commands maximum line pressure.
5. The TCM freezes transmission adaptive functions.
6. Torque management is inhibited.
7. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
8. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
9. The TCM stores DTC P0979 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 2: Listen for an audible click when the solenoid energizes.

DTC P0979

The 4-5 shift solenoid valve is located in the control valve body of the transmission. The transmission control module (TCM) selects the required gear by turning the appropriate solenoid ON or OFF, enabling the transmission to shift. Refer to Shift Solenoid Valve State and Gear Ratio .

The TCM provides voltage to the solenoid through high side driver 2 (HSD2). The TCM uses a second driver to control the solenoid ground circuit. The controlled ground driver reports feedback voltage to the TCM. When the TCM commands the 4-5 shift solenoid valve ON, the voltage of the control circuit should be approximately 0 volts. When the TCM commands the 4-5 shift solenoid valve OFF, the voltage of the control circuit should be approximately system voltage.

When the TCM detects a continuous short to voltage in the 4-5 shift solenoid valve circuit, then DTC P0980 sets. DTC P0980 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P0980 4-5 Shift Solenoid (SS) Control Circuit High Voltage

1. The engine run time is greater than 5 seconds.
2. HSD2 is commanded ON.

DTC P0980 sets when the TCM detects a short to voltage in the 4-5 shift solenoid valve circuit for 4.3 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
2. The TCM turns off power to all solenoids.
3. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
4. The TCM commands maximum line pressure.
5. The TCM freezes transmission adaptive functions.
6. Torque management is inhibited.
7. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
8. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
9. The TCM stores DTC P0980 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 2: Listen for an audible click when the solenoid energizes.

DTC P0980

While the vehicle is being driven, engine and transmission data accumulates in a random access memory (RAM) device, which cannot store data reliably when the transmission control module (TCM) powers down. Before the TCM powers down, the data is copied from RAM to an electrically-erasable programmable read-only memory (EEPROM) device, sometime referred to as non-volatile memory (NVM). Both the RAM and the EEPROM are inside the TCM. A normal function of the TCM programming is to test the EEPROM at TCM power-down by copying test data from RAM to the EEPROM and then comparing the two copies. If they do not match, DTC P1621 will set. DTC P1621 is a type A DTC.

This diagnostic procedure supports the following DTC

DTC P1621 Transmission Control Module (TCM) Long Term Memory Performance

The ignition is ON.

The TCM detects a checksum error when the RAM and EEPROM test data are compared.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) when the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
5. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
6. The TCM stores DTC P1621 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

TCM reprogramming may cause P1621 to set.

The number below refers to the step number on the diagnostic table.

1. 2: Performing this step helps verify that an external anomaly, such as Electromagnetic Interference (EMI), did not cause the code to set originally.

DTC P1621

The engine control module (ECM) sends wheel speed data to the transmission control module (TCM). The data is sent to the TCM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P1793 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P1793.

When the TCM receives invalid wheel speed data from the ECM, then DTC P1793 will set. DTC P1793 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P1793 Wheel Speed Signal

1. The engine run time is greater than 6 seconds.
2. No other CAN errors are present.

The TCM receives no valid wheel speed data from the ECM for 2 seconds.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM inhibits autograde braking.
3. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
4. The TCM stores DTC P1793 in TCM history.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

DTC P1793

Scheme 64

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The IMS input parameters represented are transmission range Signal A, Signal B, Signal C and Signal P.

If the TCM detects an invalid switch state while the engine is being started, then DTC P1815 sets. DTC P1815 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1815 Transmission Fluid Pressure (TFP) Valve Position Switch - Start in Wrong Range

1. No OSS DTC P0722 or P0723.
2. The transmission output shaft speed is less than 100 RPM.

The manual shift shaft switch assembly indicates a transitional state during the following sequence

1. The engine speed is 60 RPM or less for 0.25 second or greater.
2. The engine speed is 81-625 RPM for 0.15 second or greater.
3. The engine speed is 651 RPM or greater for 1.5 seconds or greater.
4. The transmission input shaft speed is 200 RPM or greater for 1.5 seconds or greater.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM assumes a D shift pattern.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1815 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

1. 3: All HI values, in both PARK and DRIVE, indicate the ground circuit is OPEN.
2. 5: With the transmission 20-way connector disconnected, all IMS values should indicate HI.
3. 7: If one circuit affects the other, this indicates a short between the two circuits.
4. 13: This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.

DTC P1815

Scheme 65

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the lower control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The 4 IMS input parameters represented are Signal A, Signal B, Signal C and Signal P.

If the TCM detects a short to ground on the IMS signal A, then DTC P1820 sets. DTC P1820 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1820 Internal Mode Switch A Circuit Low Voltage

1. No engine torque signal DTC P2637.
2. The engine run time is greater than 5 seconds.
3. The engine torque is 55 N.m (41 lb ft) - 450 N.m (332 lb ft).

1. The switch indicates PARK for 1 second, then
2. The switch indicates a transitional state for greater than 4 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM assumes a D shift pattern.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1820 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

1. 3: This step determines if the fault is internal or external to the transmission.
2. 4: This step determines if the engine wiring harness circuit or the TCM is at fault.
3. 5: This step determines if the automatic transmission wiring harness or the IMS is at fault.

DTC P1820

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body, within the transmission. The 4 inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The 4 IMS input parameters represented are Signal A, Signal B, Signal C and Signal P (Parity).

If the TCM detects signal B circuit HI, DTC P1822 sets. DTC P1822 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1822 Internal Mode Switch B Circuit High Voltage

1. No engine torque signal DTC P2637.
2. The engine run time is greater than 5 seconds.
3. The engine torque is greater than 55 N.m (41 lb ft).

1. The switch indicates PARK for 1 second, then
2. The switch indicates a transitional state between D2 and D3 for 4 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM assumes a D5 shift pattern.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1822 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

1. 3: This step determines if the fault is internal or external to the transmission.
2. 4: This step determines if the engine wiring harness circuit is at fault or the TCM.
3. 5: This step determines if the automatic transmission wiring harness or transmission manual shift shaft switch assembly is at fault.

DTC P1822

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The four IMS input parameters represented are Signal A, Signal B, Signal C and Signal P.

If the TCM detects the signal P circuit shorted to ground, DTC P1823 sets. DTC P1823 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1823 Internal Mode Switch P Circuit Low Voltage

1. No engine torque signal DTC P2637.
2. The engine run time is greater than 5 seconds.
3. The engine torque is greater than 25 N.m (18 lb ft).

1. The switch indicates PARK for 1 second, then
2. The switch indicates a transitional state for 5 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM assumes a D5 shift pattern.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1823 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

1. 3: This step determines if the fault is internal or external to the transmission.
2. 4: This step determines if the engine wiring harness circuit or the TCM is at fault.
3. 5: This step determines if the automatic transmission wiring harness or the transmission manual shift shaft switch assembly is at fault.

DTC P1823

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The four IMS input parameters represented are Signal A, Signal B, Signal C and Signal P.

If the TCM detects a combination of switch inputs that are invalid, then DTC P1825 sets. DTC P1825 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1825 Internal Mode Switch - Invalid Range

The engine run time is greater than 5 seconds.

The TCM detects an invalid switch range for 5 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM assumes a D5 shift pattern.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1825 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

1. 3: This step tests the transmission manual shift shaft switch assembly for an open ground circuit.
2. 5: This step tests for correct reference voltage from the TCM.

DTC P1825

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage level at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The four IMS input parameters represented are Signal A, Signal B, Signal C and Signal P.

If the TCM detects switch Signal C is high while the vehicle is being driven in a forward gear, then DTC P1826 sets. DTC P1826 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1826 Internal Mode Switch C Circuit High Voltage

1. No OSS DTCs P0722 or P0723.
2. No engine torque signal DTC P2637.
3. Vehicle speed is greater than 8 km/h (5 mph).
4. Engine torque is greater than 20 N.m (15 lb ft).
5. DTC P1826 has not passed during the current ignition cycle.
6. The gear ratio is within one of the following ranges: 3.33:1 to 3.50:1 for first gear 2.16:1 to 2.27:1 for second gear 1.56:1 to 1.64:1 for third gear 0.98:1 to 1.03:1 for fourth gear 0.73:1 to 0.77:1 for fifth gear

The TCM detects Signal C is high, while the gear ratio indicates first, second, third, fourth, or fifth gear for 3 seconds.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM assumes a D5 shift pattern.
4. The TCM freezes transmission adaptive functions.
5. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1826 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 3: This step tests the integrity of the engine harness and TCM by checking for the Signal C state change from HI to LOW. A LOW signal indicates the fault is in the internal transmission harness or the switch. A HI signal indicates the fault is in the engine harness or the TCM.

DTC P1826

Scheme 66

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through two separate solid-state devices called High Side Drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

When the TCM detects a short to ground on HSD1, then DTC P1831 sets. DTC P1831 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P1831 Pressure Control (PC)/Shift Lock Solenoid Control Circuit Low Voltage

The engine run time is greater than 5 seconds.

The TCM detects a short to ground on the HSD1 circuit when the HSD1 is commanded ON.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
5. The TCM stores DTC P1831 in TCM history.

Conditions for Clearing the DTC/DIC

1. The TCM clears the DIC when the condition no longer exists.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

DTC P1831

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through two separate solid-state devices called High Side Drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

When the TCM detects a short to voltage on HSD1, then DTC P1832 sets. DTC P1832 is a type C DTC.

This diagnostic procedure supports the following DTC

DTC P1832 Pressure Control (PC)/Shift Lock Solenoid Control Circuit High Voltage

The ignition is ON.

The TCM detects greater than 6.4 volts at the HSD1 terminal prior to commanding the HSD1 ON.

1. The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
5. The TCM stores DTC P1832 in TCM history.

1. The TCM clears the DIC when the condition no longer exists.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

DTC P1832

Scheme 67

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through 2 separate solid-state devices called high side drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

When the TCM detects a short to ground on HSD2, then DTC P1833 sets. DTC P1833 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1833 Torque Converter Clutch (TCC)/Shift Solenoid (SS) Control Circuit Low Voltage

The engine run time is greater than 5 seconds.

The TCM detects a short to ground on the HSD2 circuit when the HSD2 is commanded ON.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
2. The TCM turns off power to all solenoids.
3. The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
4. The TCM commands maximum line pressure.
5. The TCM freezes transmission adaptive functions.
6. The TCC is disabled.
7. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
8. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
9. The TCM stores DTC P1833 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
4. The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.

DTC P1833

See also:
• Shift Solenoid Valve State and Gear Ratio
• Diagnostic System Check - Vehicle
• Transmission Fluid Checking Procedure
• Intermittent Conditions
• Intermittent Conditions
• Shift Solenoid Leak Test
• 2-3 Shift Solenoid Replacement
• Diagnostic Trouble Code (DTC) List - Vehicle
• Testing for a Short to Voltage
• Wiring Repairs
• Control Module References
• Circuit Protection - Fuses
• Testing for Short to Ground
• Testing for Continuity
• Circuit Testing
• Diagnostic Trouble Code (DTC) List/Type
• Special Tools
• Automatic Transmission Fluid/Filter Replacement
• Automatic Transmission Inline 20-Way Connector End View (5L40-E)
• Component Resistance
• Automatic Transmission Related Connector End Views (5L40-E)