Buick Regal: DTC P0729-P0735, P076F, or P07D9
Diagnostic Instructions
- Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
- Review the description of Strategy Based Diagnosis:Strategy Based
Diagnosis
- An overview of each diagnostic category can be found here: Refer to
Diagnostic Procedure Instructions
DTC Descriptor
DTC P0729
6th Gear Ratio Incorrect
DTC P0730
Gear Ratio Incorrect
DTC P0731
1st Gear Ratio Incorrect
DTC P0732
2nd Gear Ratio Incorrect
DTC P0733
3rd Gear Ratio Incorrect
DTC P0734
4th Gear Ratio Incorrect
DTC P0735
5th Gear Ratio Incorrect
DTC P076F
7th Gear Ratio Incorrect
DTC P07D9
8th Gear Ratio Incorrect
Circuit/System Description
The control module calculates gear ratio based on information from various
transmission sensors and information
obtained from other control modules. If the commanded gear ratio does not match
the calculated gear ratio, a DTC
sets.
Conditions for Running the DTC
- DTC P0711, P0712, P0713, P0742, P0717, P07BF, P07C0, P0722, P077C, P077D
= Not set
- B14A Transmission Output Shaft Speed Sensor=Greater than 59 RPM
- K71 Transmission Control Module= Communication Enabled
- Ignition Voltage=9 to 32 V
- Transmission Fluid Temperature=Warmer than -20ºC (-4ºF)
- Transmission Range= Drive
- {P0729Condition 1}Transmission Gear=6th gear
- {P0729Condition 2}Transmission Gear=6th gear & Engine Torque=Greater
than 59 Nm (44 lb ft)
- {P0730Condition 1}Transmission Gear=1st Gear & Engine Torque=Less than 0
Nm (0 lb ft)
- {P0730Condition 2}Transmission Gear=1st Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P0730Condition 3}Transmission Gear=1st Gear & Engine Torque=Greater
than 59 Nm (44 lb ft) & B14C
- Transmission Input Shaft Speed Sensor=Less than 6001 RPM
{P0731}Transmission Gear=1st Gear & Engine Torque=Greater than 59 Nm (44 lb
ft) & B14C Transmission
- Input Shaft Speed Sensor =Less than 6001 RPM
- {P0732Condition 1}Transmission Gear=2nd Gear
- {P0732Condition 2}Transmission Gear=2nd Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P0733Condition 1}Transmission Gear=3rd Gear
- {P0733Condition 2}Transmission Gear=3rd Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P0734Condition 1}Transmission Gear=4th Gear
- {P0734Condition 2}Transmission Gear=4th Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P0735Condition 1}Transmission Gear=5th Gear
- {P0735Condition 2}Transmission Gear=5th Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P076FCondition 1}Transmission Gear=7th Gear
{P076FCondition 2}Transmission Gear=7th Gear & Engine Torque=Less than -20
Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
- {P07D9Condition 1}Transmission Gear=8th Gear
- {P07D9Condition 2}Transmission Gear=8th Gear & Engine Torque=Less than
-20 Nm (-15 lb ft) or Greater
than 29 Nm (21 lb ft)
Frequency the DTC runs=Continuously - After the running conditions are met -
For 2 s
Conditions for Setting the DTC
P0729, P0730, P0732, P0733, P0734, P0735, P076F, P07D9 - Condition 1
The following parameters are not within 20% of each other:Gear Ratio & Gear
Command - For 1 s - Malfunction
occurred 5 times.
P0729Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 4, 5, 7, 8 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P0730Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 3, 4 ratio - For greater
than 1 s - Malfunction occurred 5 times.
P0730Condition 3
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 5 ratio - For greater
than 1 s - Malfunction occurred 5 times.
P0731
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 4, 5 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P0732Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 3, 4, 5, 8 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P0733Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 4, 5, 7 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P0734Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 3, 5, 6 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P0735Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 3, 4, 6, 7, 8 ratio -
For greater than 1 s - Malfunction occurred
5 times.
P076FCondition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 3, 5, 6, 8 ratio - For
greater than 1 s - Malfunction occurred 5
times.
P07D9Condition 2
Gear Ratio=Incorrect gear ratio - Within 4% of gear 2, 5, 6, 7 ratio - For
greater than 1 s - Malfunction occurred 5
times.
Actions Taken When the DTC Sets
DTCs listed in the DTC Descriptor Category=Type A DTC - Exceptions listed
below - Additional actions taken:
DTC P0730=Type C DTC
- Autostart/Autostop=Disabled - If equipped
- Fail-Safe Mode=Enabled
- Learning=Disabled
Conditions for Clearing the DTC
DTCs listed in the DTC Descriptor Category=Type A DTC
DTC P0730=Type C DTC
Reference Information
Schematic: Reference
Refer to Automatic Transmission Controls Wiring Schematics
Connector End View: Reference
Refer to Component Connector End View Index
Component View: Reference
Refer to Disassembled Views
Description and Operation
Refer to Transmission General Description
Electrical Information: Reference
- Refer to Circuit Testing
- Refer to Connector Repairs
- Refer to Testing for Intermittent Conditions and Poor Connections
- Refer to Wiring Repairs
DTC Type: Reference
Refer to Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool: Reference
Refer to Control Module: References
Circuit/System Verification
1. Ignition - On / Vehicle - In Service Mode
2. Verify there are no DTCs set related to the following system/component:
- Q27A Pressure Control Solenoid Valve 1
- Q27B Pressure Control Solenoid Valve 2
- Q27C Pressure Control Solenoid Valve 3
- Q27D Pressure Control Solenoid Valve 4
- Q27E Pressure Control Solenoid Valve 5
- Q27F Pressure Control Solenoid Valve 6
- Q32A Shift Solenoid Valve 1
- Q32B Shift Solenoid Valve 2
- If other DTCs are set
Refer to: Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If no other DTCs are set
3. Verify the condition does not exist:Incorrect fluid level or condition -
Transmission - Refer to Transmission
Fluid Level and Condition Check
Repair or replace as necessary.
- Go to next step: If no condition exists
4. Verify the condition does not exist:Incorrect pressure - Transmission -
Refer to Line Pressure Check
Replace the component:T12 Automatic Transmission Assembly
- Go to next step: If no condition exists
5. Clear the DTCs.
6. Perform the configuration/reset function: Refer to Learned Values Reset
7. Road test the vehicle. - Refer to Road Test.
8. Verify DTC P0729, P0730, P0731, P0732, P0733, P0734, P0735, P076F, P07D9 is
not set.
- {Test failed 1 time (s) }If any of the DTCs are set
- Replace the component: K71 Transmission Control Module
- Refer to:Step 5
- {Test failed 2 time (s) }If any of the DTCs are set
- Replace the component: Control Valve Body
- Refer to:Step 5
- {Test failed 3 time (s) }If any of the DTCs are set
- Replace the component: T12 Automatic Transmission Assembly
- Refer to:Step 5
- Go to next step: If none of the DTCs are set
9. Operate the vehicle within the Conditions for Running the DTC. You may
also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Verify the DTC does not set.
Refer to:Step 1
- Go to next step: If the DTC is not set
10. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair: Refer
to Diagnostic Repair Verification
- Refer to Control Valve Body Replacement
- Refer to Transmission Replacement
- For control module replacement, programming, and setup: Refer to Control
Module: References
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosi
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosi
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosi
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Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic
procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic
category.
DTC Descriptors
DTC P222