Part 2 of 2
Code P0731(51) - Excludes gear train failures which should be obvious upon disassembly- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- Valve body - # 1, # 2, and/or # 4 check ball
- L-R switch valve sticking
- Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57) Solenoid/TRS assembly (stuck solenoid(s))
- Failed or intermittent slipping UD clutch may also set P0732(52) or P0733(53)
- UD seal leakage
- Sticky UD accumulator seals - Worn reaction shaft support seal rings
- Failed or slipping L-R clutch - may have code P0736(50)
- L-R seal leakage
- Sticky L-R accumulator seals
Code P0732(52) - Excludes gear train failures which should be obvious upon disassembly
- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- Valve body - # 1, # 2, # 4, # 5 and/or # 7 check ball
- Solenoid/TRS assembly - may also set codes P0846(54) and/or P0845(A2)
- Failed or slipping 2nd clutch - 2nd clutch seal leakage - Sticky 2nd clutch accumulator seals
- Failed or intermittent slipping UD clutch may also set code P0731(51) and/or P0733(53) - UD clutch seal leakage
- Worn input hub bushing
- Sticky UD clutch accumulator seals
- Worn reaction shaft support seal rings
Code P0733(53) - Excludes geartrain failures which should be obvious upon disassembly
- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- Valve body - # 1, # 2, and/or # 6 check ball
- Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57)
- Solenoid/TRS assembly - may also set codes P0871(84) and/or P0870(A4)
- Failed or slipping OD clutch - may also set code P0734(54)
- OD clutch inner and outer lip seal leakage - Sticky OD clutch accumulator seals
- Worn reaction shaft support seal rings
- Failed or intermittent slipping UD clutch may also set codes P0731(51) and/or P0732(52)
- UD seal leakage
- Worn input hub bushing
- Sticky UD clutch accumulator seals
- Worn reaction shaft support seal rings
Code P0734(54) - Excludes gear train failures which should be obvious upon disassembly
- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- Valve body - # 1, # 2, # 5 and/or # 6 check ball
- Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57)
- Solenoid/TRS assembly - may also set codes P0988(88) and/or P0987(A8)
- Failed or slipping OD clutch - may also set code P0733(53)
- OD clutch inner and outer lip seal leakage - Sticky OD clutch accumulator seals
- Worn reaction shaft support seal rings
- Failed or intermittent slipping 4th clutch - 4th clutch seal leakage
- Sticky 4th clutch accumulator seals
- Worn reaction shaft support seal rings
Code P1736(55) - Excludes gear train failures which should be obvious upon disassembly
- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- Valve body - # 1, # 4 and/or # 5 check ball
- Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57)
- Solenoid/TRS assembly - may also set codes P0876(90) and/or P0875(BO)
- Failed or intermittent slipping UD clutch may also set codes P0731(51) and/or P0732(52)
- UD seal leakage
- Worn input hub bushing
- Sticky UD clutch accumulator seals
- Worn reaction shaft support seal rings
- Failed or intermittent slipping 4th clutch
- 4th clutch seal leakage
- Sticky 4th clutch accumulator seals
- Worn reaction shaft support seal rings
Codes P0715(56) and P0720(57)
- Failed input or output speed sensor
- Shorted or open wiring between TCM and speed sensor(s)
- Connector problems at 60-way TCM connector and/or speed sensor connector(s)
- Transmission Solenoid/TRS Assembly has an internal short to the Speed Sensor Ground circuit (should also set a P1794 and P1799).
Code P1794(58)
- Open or shorted speed sensor ground (speed sensor ground is different from chassis ground)
- Open or shorted Temperature Sensor wiring to TRS
- Transmission Solenoid/TRS Assembly has an internal short to the Speed Sensor Ground circuit
- TRS - Will also set code P1799(74)
- TCM
Code P0735(59) - Excludes gear train failures which should be obvious upon disassembly
- If code P0944(35) or any line pressure DTC's are set, diagnose these first
- These codes may also be set with the DTC P1790(36), P0846(82), P0871(84), P0845(A2), P0870(A4), perform these diagnostics first.
- Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57)
- Solenoid/TRS assembly (stuck solenoid(s))
- Failed or slipping OD clutch - OD seal leakage
- Failed or slipping 2C clutch - 2C seal leakage
NAME OF CODE: P2700, P2701, P2702, 2703, 2704 (60, 61, 62, 63, 64) - Inadequate Element Volume
When Monitored: Whenever the engine is running, the clutch volume is updated during the requested shift. Set Condition: Note: Transmission temperature must be 43 °C (110 °F) to update all volumes.
- P2700 - When the LR volume falls below 16, the LR volume is updated during a 3-1 or 2-1 manual downshift with the TPS angle below 5 degrees.
- P2701 - When the 2C volume falls below 5, the 2C volume is updated during a 3-2 kick-down with the TPS angle between 10 and 54 degrees.
- P2702 - When the OD volume falls below 5, the OD volume is updated during a 2-3 upshift with the TPS angle between 10 and 54 degrees.
- P2703 - When the UD volume falls below 11, the UD volume is updated during a 4-3 kickdown with the TPS angle between 30 and 54 degrees.
- P2704 - When the 4C volume falls below 30, the 4C clutch volume is updated when doing a 3-4 shift with throttle angle between 10° and 54'. The transmission temperature must be above 43 °C (110 °F). The clutch volume should be between 30 and 85.
Theory of Operation: The volumes of the transmission fluid needed to apply the friction elements are continuously monitored and learned for adaptive controls. As the clutch friction material wears, the volume of fluid needed to apply the clutch increases. The following are typical clutch volumes, the clutches may be damaged if the volumes are greater or less than the specified below:
2C clutch volume - between 25 and 85
OD clutch volume - between 30 and 100 4C clutch volume - between 30 and 85
UD clutch volume - between 30 and 100
Transmission Effects: These codes usually set with other DTC's, which indicates an internal transmission problem.
Possible Causes:
- Clutch pack clearance out of spec
- Snap ring out of position or broken
- Broken return spring
- Hydraulic leak into clutch circuit with near zero volume
NAME OF CODE: P1715(65) - Restricted Port in T3 Range
When Monitored: Whenever the Engine is running and the Manual valve is in the T3 range.
Set Condition: The code is set if the conditions for a code 47 are present when the manual valve is in the T3 range.
Theory of Operation: The conditions to set a DTC 47 are easily satisfied while in the T3 range. There is no problem with the transmission itself if this code is set.
Transmission Effects: The transmission will go into neutral when this code is set. If the driver puts the shifter in neutral and back to drive, the transmission will operate normally.
Possible Causes:
- Manual linkage out of adjustment, causing T3 range while shifter is in OD.
- Driver resting hand on shift lever while driving, causing T3 range.
NAME OF CODE: P1799(74) - Calculated Oil Temp in Use
When Monitored: Whenever the Engine is running.
Set Condition: The code is set if any of the following conditions exist for three consecutive key starts:
- The Temperature Sensor voltage is out of range (below 0.07 volts or greater than 4.94 volts)
- Continuous erratic Temperature Sensor voltage is sensed.
- The Temperature Sensor temperature stays below 27°C (80°F) for an extended period of time.
Theory of Operation: The TCM uses a Temperature Sensor to monitor the transmission's sump temperature. This temperature is used to determine which shift schedule the TCM is to use. If the Temperature Sensor circuit fails to operate properly the TCM will use the calculated oil temperature routine found in prior model year TCM's. If this occurs for three consecutive key starts, the code will be set. The TCM will then test the Temperature Sensor circuit after every 35th OBDII/EUROIII warm-up start. If the Temperature Sensor circuit is OK, the Temperature Sensor data is used in place of the Calculated Oil Temperature Routine.
Transmission Effects: If the Temperature Sensor indicates a temperature below -18 °C (0 °F) or above 116 °C (240 °F) at start up, the TCM compares the calculated oil temperature to the indicated oil temperature. If the calculated oil temperature differs significantly from the Temperature Sensor value, the calculated oil temperature will be used for that key start. This code does not cause the transmission to go into limp-in mode.
Possible Causes:
- Transmission temperature sensor signal circuit short to ground, short to voltage, or open circuit.
- Speed sensor ground circuit shorted to ground, shorted to voltage, or open circuit.
- Temperature Sensor
- TCM
NAME OF CODE: P0218(75) - High Temperature Operation Activated
When Monitored: Whenever the engine is running.
Set Condition: Immediately when the Overheat shift schedule is activated.
Theory of Operation: If the transmission oil temperature rises above 116 °C (240 °F), the over
heat shift schedule is activated, refer to the Transmission Operation as a function of Transmission Oil Temperature. The code is an information code only and is being set to aid the technician in determining root cause of a customer driveability issue. The code is also intended to alert the technician to determine if a cooling system malfunction has occurred or if an additional transmission air to oil cooler should be added to the vehicle if the customer regularly drives in a manner that overheats the transmission. Extended operation above 116 °C (240 °F) will reduce the durability of the transmission and should be avoided. Correcting the cooling system malfunction or installing an additional transmission oil cooler will improve transmission durability especially for customers who operate in city/construction stop and go traffic, tow trailers regularly, drive aggressively in low gear or drive regularly in mountainous areas.
Transmission Effects: Information only code. Overheat shift schedule was activated, no limp-in condition occurs. See description of overheat shift schedule.
Possible Causes:
- Transmission Overfilled with Oil
- Engine cooling fan failure
- Engine thermostat stuck closed
- Radiator corroded or packed with dirt
- Transmission cooler corroded or packed with dirt
- Transmission fan not functioning properly
- Transmission Oil Cooler Plugged
- Customer driving pattern requires additional transmission cooling
NAME OF CODE: P0884(76) - Power-Up at Speed
When Monitored: When TCM (Transmission Control Module) initially powers-up.
Set Condition: If the TCM powers up and senses a valid forward gear PRNDL code and the output RPM is above 800 RPM approx. 32 km/h (20 MPH) the code will be set.
Theory of Operation: If a vehicle loses power to the TCM, the solenoids will go to their respective power off state. Some solenoids are normally vented and some are normally applied in their power off state. The transmission is designed to be in 3rd gear with all of the solenoids in this state. However, if power is restored, the TCM will powerup and normal operation will be restored.
This code identifies that power to the TCM was restored when the gear selector was in a "Drive" position while the vehicle was moving at speeds above 32 km/h (20 MPH). This code does not indicate a problem with the transmission or TCM, instead, it suggests intermittent problems in the fused ignition switch output, fused B(+), or ground circuits to the TCM. Alternately, if a person performs a rolling restart maneuver, the code can be set. Therefore it is critical that this DTC be investigated if the vehicle is experiencing intermittent 3rd gear operation and a subsequent return to normal operation.
Transmission Effects: No limp-in, although the symptom might be described as an intermittent limp-in. Code is for information only when trying to diagnosis intermittent 3rd gear operation and a subsequent return to normal operation.
Possible Causes:
- No Problem if vehicle is started in "neutral" at speeds above 32 km/h (20 mph) and shifted quickly to a forward gear position.
- Quick key off then on while driving is any forward gear.
FOR INTERMITTENT 3rd GEAR OPERATION AND THEN A SUBSEQUENT RETURN TO NORMAL OPERATION WITHOUT CYCLING THE IGNITION KEY
- Intermittent Direct Battery (Fused B(+)) connection between TCM (60-way pin 56) and battery.
- Intermittent Fused Ignition Switch Output between TCM (60-way pin 11) and ignition switch.
- Intermittent Ground to TCM (60 way pins 53 and 57).
NAME OF CODE: P0890(80) - Switched Battery
When Monitored: Ignition key is turned from "OFF" position to "RUN" position and/or ignition key is turned from "CRANK" position to "RUN" position.
Set Condition: This code is set if the Transmission Control Module (TCM) senses voltage on any of the pressure switch inputs prior to the TCM energizing the relay.
Theory of Operation: The Transmission control relay is used to supply power to the solenoids and pressure switches when the transmission is in normal operating mode. When the relay is off, no power is supplied and the transmission is in "limpin" mode. The relay output is fed back to the TCM through pins 16, 17 and 38. It is referred to as Transmission Control Relay Output".
Immediately after a controller reset (ignition key turned to the "run" position or after cranking engine), the TCM verifies that the relay contacts are open by checking for no voltage at the transmission control relay output terminals. After this is verified, the voltage at the pressure switches is checked. There should be no voltage on the pressure switches at this time. The TCM will then activate the relay.
Transmission Effects: The MIL will illuminate and the transmission system will default to the Immediate Shutdown routine.
Possible Causes:
- Short to battery on one or more pressure switch sense circuits.
- TCM connector problems.
- Solenoid/TRS connector problems.
- TCM.
NAME OF CODE: P0841(81) - LR Pressure Switch Sense Circuit
P0846(82) 2C Pressure Switch Sense Circuit
P0871(84) - OD Pressure Switch Sense Circuit
P0988(88) - 4C Pressure Switch Sense Circuit
P0876(90) - LTD Pressure Switch Sense Circuit
When Monitored: Whenever the engine is running.
Set Condition: The appropriate code is set if one of the pressure switches are open or closed at the wrong time in a given gear (see chart below).
Theory of Operation: The Transmission system uses five pressure switches to monitor the fluid pressure in the LR, 2C, 4C, UD, and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown below.
LR pressure switch opens above 150 output RPM in 1st gear and closes below a 100 output RPM.
Transmission Effects: The MIL will illuminate and the transmission system will default to the Immediate shutdown routine.
Possible Causes:
- If code P0944(35) is present, perform code P0944(35) diagnostic procedures
- Transmission fluid filter improperly installed (Seal installed onto filter neck instead of into pump bore, seal not fully seated against pump bore housing, filter neck not engaged into pump, bolts loose or O-ring missing or damaged)
- Reverse carrier snap ring dislodged (typically sets on heavy throttle acceleration from a dead stop)
- Pressure switch sense circuit open or shorted to ground between TCM and Solenoid/TRS assembly
- Pressure switch sense circuit shorted to battery
- Pressure switch
- Loose valve body bolts
- Plugged filter - internal transmission or torque converter failure
- Check ball not seating or damaged.
- Solenoid malfunction (If set with corresponding Solenoid DTC. Ie: 2C Pressure switch set with 2C solenoid)
- Oil Pump (Code P0841(81) only)
- TCM
NAME OF CODE: P0845(A2) - 2C Hydraulic Pressure test failure
P0870(A4) OD Hydraulic Pressure test failure
P0987(A8) - 4C Hydraulic Pressure test failure
P0875(BO) - LTD Hydraulic Pressure test failure
When Monitored: In any forward gear with engine speed above 1000 RPM shortly after a shift and every minute thereafter.
Set Condition: Immediately after a shift into a forward gear, with engine speed above 1000 RPM, the TCM momentarily turns on element pressure to the clutch circuits that do not have pressure to identify that the appropriate pressure switch closes. If the pressure switch does not close it is tested again. If the switch does not close the second time, the appropriate code is set.
Theory of Operation: The Transmission Control Module (TCM) tests the pressure switches when they are off. The test verifies that the switches are operational (They will close with pressure applied). The TCM verifies that the switch closes when the corresponding element is applied. If a switch fails to close, it is re-tested. If it fails the second test, the code is set. Transmission Effects: The MIL will illuminate and the transmission system will default to the orderly Shutdown routine
Possible Causes:
- Line Pressure Sensor
- Pressure switch sense circuit shorted to battery between TCM and solenoid/TRS assembly.
- Solenoid malfunction (If set with corresponding Solenoid DTC. Ie: 2C Hydraulic Pressure switch set with 2C solenoid)
- Low oil pressure
- Pressure switch
NAME OF CODE: P0750(CI) - LR Solenoid Circuit
P0755(C2) - 2C Solenoid Circuit
P0760(C3) - OD Solenoid Circuit
P0770(C4) - 4C Solenoid Circuit
P0765(C5) - LTD Solenoid Circuit
P2706(C6) - MS Solenoid Circuit
When Monitored: Initially at power-up, then every 10 seconds thereafter. They will also be tested immediately after a gear ratio or pressure switch error is detected.
Set Condition: Three consecutive solenoid continuity test failures, or one failure if test is run in response to a gear ratio or pressure switch error.
Theory of Operation: Six solenoids are used to control the friction elements (clutches). The continuity of the solenoid circuits are periodically tested. Each inactive solenoid is turned on for a few milliseconds, then off. Each active solenoid is turned off for a few milliseconds, then on. This pulsing of voltage to the solenoid causes an inductive spike which can be sensed by the TCM. If an inductive spike is not sensed by the Transmission Control Module (TCM) during the continuity check, it is tested again. If the test fails three consecutive times, the appropriate code is set, If the solenoid test is run in response to a gear ratio or pressure switch error, one failure will result in setting the appropriate code.
Transmission Effects: The MIL will illuminate and the transmission system will default to the Immediate Shutdown routine.
Possible Causes:
- Open or shorted solenoid circuit(s) between TCM and solenoid/TRS assembly.
- Open ground circuit.
- TCM connector problems.
- Solenoid/TRS connector problem.
- Solenoid/TRS assembly.
- TCM
NAME OF CODE: P0867(C8) - Line Pressure Fault
P0868(C9) - Line Pressure Low
P0869(CB) - Line Pressure High
When Monitored: Continuously with engine running.
Set Condition: The TCM has an internal error counter for each DTC above. When any of the counters reaches a preset threshold, the appropriate code is set.
Theory of Operation: Line pressured is controlled by the TCM. It is measured by the Line Pressure Sensor (LPS) and regulation is achieved by changing the duty cycle of the Pressure Control Solenoid (PCS). (5% duty cycle , solenoid off max line pressure, 62% duty cycle , solenoid on min line pressure). The TCM calculates the desired line pressure based on inputs from the transmission and engine. The TCM calculates torque input to the transmission and uses it as the primary input to the desired line pressure calculation. This is called Torque Based Line Pressure. In addition, the line pressure is set to a preset level 827 or 931 kPa (120 or 135 PSI) during shifts and in Park and Neutral to ensure consistent shift quality. The desired line pressure is continuously being compared to the actual line pressure. If the actual line pressure is consistently higher than the target, the line pressure high DTC P0869(CB) will be set. If the actual line pressure is consistently lower than the target, the line pressure low DTC P0868(C9) will be set. If it is consistently out of range, but not consistently high or low, it is considered out of range and the line pressure error DTC P0867(C8) will be set.
Transmission Effects: The transmission system will default to open loop line pressure control resulting in a fixed PCS duty cycle. This duty cycle will change slightly depending on temperature and current gear.
Possible Causes:
- Sticking Regulator Valve
- Pressure Control Solenoid
- Line Pressure Sensor.
- Oil pump
- Plugged Filter
- 5V supply circuit to Line Pressure Sensor open (Sensor reading will read a constant value between 586 and 655 kPa (85 and 95 PSI)
- TCM
NAME OF CODE: P0932(CA) - Line Pressure Sensor Fault
When Monitored: Continuously with engine running.
Set Condition: If the Line Pressure Sensor (LPS) voltage is below 0.35 volts or above 4.75 volts the code will be set.
Theory of Operation: Line pressured is controlled by the TCM. It is measured by the LPS and regulation is achieved by changing the duty cycle of the Pressure Control Solenoid (PCS) (5% duty cycle , solenoid off , max line pressure, 62% duty cycle , solenoid on , min line pressure). This sensor is continuously checked for out of range voltage by the TCM.
Transmission Effects: The Transmission system will default to open loop line pressure control resulting in a fixed PCS duty cycle. This duty cycle will change slightly depending on temperature and current gear.
Possible Causes:
- LPS signal circuit shorted to ground, shorted to voltage, or open.
- 5-volt supply circuit shorted to ground, shorted to voltage, or open.
- Open sensor ground
- Line Pressure Sensor