Flow of Diagnosis
Diagnostic Strategy
Troubleshooting an electronically controlled automatic transmission is simplified by using the proven method of diagnosis. One of the most important things to remember is that there is a definite procedure to follow.
NOTE: Do not take any short cuts or assume that critical checks or adjustments have already been made.
Follow the procedures as written to avoid missing critical components or steps.
Use the Diagnostic Flow Chart as a guide and follow the steps as indicated.
Preliminary Inspection
^ Know and understand the customer's concern.
^ Verify the concern by operating the vehicle.
^ Check the fluid levels and condition.
^ Check for non-factory fitted items.
^ Check shift linkages for correct adjustment.
Diagnostics
^ Carry out on-board diagnostic procedures key on engine off (KOEO) and key on engine running (KOER).
^ Record all diagnostic trouble codes (DTCs).
^ Repair all non-transmission codes first.
^ Repair all transmission codes second.
^ Erase all continuous codes and attempt to repeat them.
^ Repair all continuous codes.
^ If only pass codes are obtained, proceed to Diagnosis by Symptom Index for further information and diagnosis.
Follow the diagnostic sequence to diagnose and repair the concern the first time.
Diagnostic Flow Chart
Preliminary Inspection
The following items must be checked prior to beginning the diagnostic procedures:
Know and Understand the Concern
In order to correctly diagnose a concern, first understand the customer complaint or condition. Customer contact may be necessary in order to begin to verify the concern. Understand the conditions as to when the concern occurs, for example:
^ hot or cold vehicle temperature.
^ hot or cold ambient temperature.
^ vehicle driving conditions.
^ vehicle loaded/unloaded.
After understanding when and how the concern occurs, proceed to verify the concern.
Verification of Condition
This section provides information that must be used in both determining the actual cause of customer concerns and performing the appropriate repair procedures.
The following procedures must be used when verifying customer concerns for the transmission.
Determine Customer Concern
NOTE: Some transmission conditions can cause engine concerns. An electronic pressure control short circuit can cause engine misfiring. The torque converter clutch not disengaging will stall the engine.
Determine customer concerns relative to vehicle use and dependent driving conditions, paying attention to the following items:
^ hot or cold vehicle operating temperature
^ hot or cold ambient temperatures
^ type of terrain
^ vehicle loaded/unloaded
^ city/highway driving
^ upshift
^ downshift
^ coasting
^ engagement
^ noise/vibration
Check Fluid Level and Condition
CAUTION: The vehicle should not be driven if the fluid level is low or internal failure can result.
NOTE: If the vehicle has been operated for an extended period of time at high speeds, city traffic, hot weather, or pulling a trailer, the fluid needs to cool down 30 minutes to obtain an accurate reading.
This vehicle is not equipped with a fluid level indicator. An incorrect level may affect the transmission operation and could result in transmission damage. To correctly check and add fluid to the transmission, refer to Transmission Fluid Drain and Refill]
High Fluid Level
A fluid level that is too high may cause the fluid to become aerated due to the churning action of the rotating internal parts. This will cause erratic control pressure, foaming, loss of fluid from the vent tube and possible transmission damage. If an overfill reading is indicated, refer to [Transmission Fluid Drain and Refill]
Low Fluid Level
A low fluid level could result in poor transmission engagement, slipping, or damage. This could also indicate a leak in one of the transmission seals or gaskets.
Adding Fluid
CAUTION: The use of any other type of transmission fluid than specified can result in transmission damage.
If fluid needs to be added, add fluid in 0.25L (1/2 pint) increments through the fill hole opening. Do not overfill the fluid. For fluid type, refer to the General Specification chart in this section.
Fluid Condition Check
1. Check the fluid level. For additional information, refer to [Transmission Fluid Drain and Refill]
2. Observe the color and the odor. The color under normal circumstances should be dark reddish, not brown or black.
3. Allow the fluid to drip onto a facial tissue and examine the stain.
4. If evidence of solid material is found, the transmission fluid pan should be removed for further inspection.
5. If fluid contamination or transmission failure is confirmed by the sediment in the bottom of the transmission fluid pan, the transmission must be disassembled and completely cleaned.
6. Carry out diagnostic checks and adjustments; refer to diagnosis symptom chart in this section.
Torque Converter Diagnosis
Prior to installing a new transmission, all diagnostic procedures must be followed. This is to prevent the unnecessary replacement of good transmission. Only after a complete diagnostic evaluation can the decision be made to install a new transmission.
Begin with the normal diagnostic procedures as follows:
1. Preliminary Inspection.
2. Know and Understand the Customer Concern.
3. Verify the Concern-Carry out the Torque Converter Clutch Operation Test; refer to Torque Converter Operation Test in this section.
4. Carry out Diagnostic Procedures.
^ Carry out the Stall Speed Test; refer to Stall Speed Test in this section.
^ Carry out the Diagnosis by Symptom Index; refer to Diagnosis by Symptom in this section.
Use the index to locate the appropriate routine that best describes the symptom(s). The routine will list all possible components that may cause or contribute to the symptom. Check each component listed; diagnose and service as necessary before servicing the torque converter.
Torque Converter Operation Test
This test verifies that the torque converter clutch control system and the torque converter are operating correctly.
1. Carry out the Quick Test, refer to Diagnosis by Symptom in this section. Check for DTCs. Refer to the Diagnostic Trouble Code Chart.
2. Connect a tachometer to the engine.
3. Bring the engine to normal operating temperature by driving the vehicle at road speeds for approximately 15 minutes in (D) position.
4. After normal operating temperature is reached, maintain a constant vehicle speed of about 50 mph (80 km/h) and tap brake pedal with the left foot.
5. The engine rpm should increase when brake pedal is tapped, and decrease about five seconds after pedal is released. If this does not occur, refer to Torque Converter Operation Concerns in the Diagnosis by Symptom Index.
6. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, refer to Torque Converter Operation Concerns in the Diagnosis by Symptom section. Repair as necessary. If the vehicle does not stall in (D), refer to Diagnosis by Symptom.
Visual Inspection
This inspection will identify modifications or additions to the vehicle operating system that may affect diagnosis. Inspect the vehicle for non Jaguar factory fitted devices such as:
^ electronic fitted items:
Air conditioning
Generator (alternator)
Engine turbo
Cellular telephone
Cruise control
CB radio
Linear booster
Backup alarm signal
Computer
^ Vehicle modification:
These items, if not installed correctly, will affect the powertrain control module, or transmission function. Pay particular attention to non-factory fitted wiring splices in the PCM harness or transmission wiring harness, abnormal tire size, or differential ratio changes.
^ leaks; refer to Leakage Inspection in this section.
^ correct linkage adjustments.
Shift Linkage Check
Check for a misadjustment in shift linkage by matching the detents in the transmission range selector lever with those in the transmission. If they match, the misadjustment is in the indicator. Do not adjust the shift linkage.
Hydraulic leakage at the manual control valve can cause delay in engagements and/or slipping while operating if the linkage is not correctly adjusted; refer to <~307~05] for shift linkage adjustment.
Check TSBs
Refer to all technical service bulletins, which pertain to the transmission concern and follow the procedure as outlined.
Transmission Drive Cycle Test
NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws.
NOTE: The Transmission Drive Cycle Test must be followed exactly. Transmission failure must occur four times consecutively for shift error DTC code to be set, and five times consecutively for continuous torque converter clutch code to set.
NOTE: When carrying out the Transmission Drive Cycle Test, refer to the Solenoid Application Chart for correct solenoid operation.
Using the approved Jaguar Diagnostic System carry out Transmission Drive Cycle Test for checking continuous codes.
1. Record and then erase Stored Test codes.
2. Warm engine to normal operating temperature.
3. Make sure transmission fluid level is correct.
4. With transmission in D4 position, moderately accelerate from stop to 50 mph (80 km/h). This allows the transmission to shift into fifth gear. Hold speed and throttle open steady for a minimum of 15 seconds.
5. With transmission in fifth gear and maintaining steady speed and throttle opening, lightly apply and release brake to operate stoplamps. Then hold speed and throttle steady for a minimum of five seconds.
6. Brake to a stop and remain stopped for a minimum of 20 seconds.
7. Repeat steps 4 through 6 at least five times.
8. Carry out Transmission Drive Cycle Test and record continuous DTCs.
After On-Board Diagnostics
NOTE: The vehicle wiring harness, powertrain control module and non-transmission sensors may affect transmission operations. Repair these concerns first.
After the on-board diagnostic procedures are completed, repair all DTCs.
Begin with non-transmission related DTCs, then repair any transmission related DTCs. Refer to the Diagnostic Trouble Code Chart for information on condition and symptoms. This chart will be helpful in referring to the correct manual(s) and aids in diagnosing internal transmission concerns and external non-transmission inputs. The pinpoint tests are used in diagnosing transmission electrical concerns. Make sure that the vehicle wiring harness and the PCM are diagnosed as well.
Before Pinpoint Tests
NOTE: Prior to entering pinpoint tests, check the powertrain control module wiring harness for correct connections, bent or broken pins, corrosion, loose wires, correct routing, correct seals and their condition. Check the PCM, sensors and actuators for damage.
NOTE: If a concern still exists after electrical diagnosis, refer to Diagnosis by Symptom in this section.
If DTCs appear while carrying out the on-board diagnostics, refer to the Diagnostic Trouble Code Chart for the appropriate repair procedure. Prior to entering pinpoint tests, refer to any TSBs for transmission concerns.
Diagnostic Trouble Code Chart
Diagnostic Trouble Code Chart Part 1 of 12
Diagnostic Trouble Code Chart Part 2 of 12
Diagnostic Trouble Code Chart Part 3 of 12
Diagnostic Trouble Code Chart Part 4 of 12
Diagnostic Trouble Code Chart Part 5 of 12
Diagnostic Trouble Code Chart Part 6 of 12
Diagnostic Trouble Code Chart Part 7 of 12
Diagnostic Trouble Code Chart Part 8 of 12
Diagnostic Trouble Code Chart Part 9 of 12
Diagnostic Trouble Code Chart Part 10 of 12
Diagnostic Trouble Code Chart Part 11 of 12
Diagnostic Trouble Code Chart Part 12 of 12
Stall Speed Test
This test checks operation of the following items:
^ torque converter clutch
^ forward clutch
^ low one way clutch (OWC) assembly
^ engine performance
WARNING: APPLY THE PARKING BRAKE FIRMLY WHILE CARRYING OUT EACH STALL TEST.
NOTE: The Stall Speed Test should be carried out with the engine and transmission at normal operating temperatures.
1. Connect tachometer to the engine.
2. CAUTION: After testing each of the following ranges D4, 3, 2 and R. move the transmission range selector lever to N (NEUTRAL) and run the engine at 1000 rpm for about 15 seconds to allow the torque converter to cool before testing the next range.
CAUTION: Do not maintain wide open throttle in any range for more than five (5) seconds.
CAUTION: If the engine rpm recorded by the tachometer exceeds maximum specified rpm, release the accelerator pedal immediately. Clutch or band slippage is indicated.
NOTE: Prolonged use of this procedure may set Diagnostic Trouble Code P0712, P1783. After Carrying out Stall Speed Test run OBD Test and clear DTCs from memory.
Press accelerator pedal to floor (WOT) in each range. Record rpm reached in each range. Stall speeds should be as follows:
Stall Speed Diagnosis Chart
Fluid Leakage in Torque Converter Area
In diagnosing and correcting fluid leaks in the front pump support and gear and torque converter area, use the following procedures to locate the exact cause of the leakage. Leakage at the front of transmission, as evidenced by fluid around the torque converter housing, may have several sources. By careful observation it is possible, in many instances, to pinpoint the source of leak before removing the transmission from the vehicle. The paths, which the fluid takes to reach the bottom of the torque converter housing, are shown in the illustration. The five steps following correspond with the numbers in the illustration.
1. Fluid leaking by the pump seal lip will tend to move along the impeller hub and onto the back of the impeller housing. Except in the case of a total seal failure, fluid leakage by the lip of the seal will be deposited on the inside of the torque converter housing only, near the outside diameter of the housing. Fluid from the vent assembly may move along the impeller hub and onto the back of the impeller housing. Fluid from a converter hub weld leak will move along a path on the inside of the converter housing.
2. Fluid leakage by the outside diameter of the pump seal and pump body will follow the same path that leaks by the inside diameter of the pump seal follow. Fluid from a converter hub weld leak will move along a path on the inside of the converter housing.
3. Fluid that leaks by a pump-to-case screw or pump gasket will be deposited on the inside of the torque converter housing only. Fluid will not be deposited on the back of the torque converter.
4. Fluid leakage from the converter drain plug, (model-dependent) converter seal weld or converter-to-flywheel stud weld will appear at the outside diameter of the torque converter on the back face of the flywheel, and in the converter housing only near the flywheel. Fluid leaks from the torque converter will leave a ring of fluid around the inside of the torque converter housing.
5. NOTE: White facial tissue paper may aid in determining the color (red is transmission fluid) and source of the leaking fluid.
Engine oil leaks are sometimes incorrectly diagnosed as transmission pump gasket leaks. The following areas of possible leakage should also be checked to determine if engine oil leakage is causing the concern.
1. Leakage at the valve cover gasket may allow oil to flow over the torque converter housing or seep down between the torque converter housing and cylinder block causing oil to be present in or at the bottom of the torque converter housing.
2. Oil galley plug leaks will allow oil to flow down the rear face of the cylinder block to the bottom of the torque converter housing.
3. Leakage at the crankshaft rear oil seal will work back to the flywheel, and then into the torque converter housing.
4. Leakage at the oil pressure sensor.
Leak Check Test
1. Remove the fluid drain tube and note the color of the fluid. Original factory fill fluid is dyed red to aid in determining if leakage is from the engine or transmission. The red color should assist in pinpointing the leak.
2. Clean off any fluid from the top and bottom of the torque converter housing, of the case, and the rear face of the engine and oil pan. Clean the torque converter area by washing with a suitable nonflammable solvent and blow dry with compressed air.
3. Wash out the torque converter housing, and the front of the flywheel. The torque converter housing may be washed out using cleaning solvent and a squirt-type oil can. Blow all washed areas dry with compressed air.
4. Start and run the engine until the transmission reaches its normal operating temperature. Observe the back of the cylinder block and the top of the torque converter housing for evidence of fluid leakage. Raise the vehicle on a hoist; and run the engine at fast idle, then at engine idle, occasionally shifting to the D4 and REVERSE positions to increase pressure within the transmission. Observe the front of the flywheel, back of the cylinder block (in as far as possible), and inside the torque converter housing and front of the case. Run the engine until fluid leakage is evident and the probable source of leakage can be determined.
Leak Check Test With Ultraviolet Light
Fluid soluble anodyne or fluorescent dyes premixed at the rate of 2.5ml (1/2 teaspoon) of dye powder to 0.24L (1/2 pint) of automatic transmission fluid have proven helpful in locating the source of fluid leakage. Such dyes may be used to determine whether an engine fluid or transmission fluid leak is present, or if the fluid in the transmission fluid cooler hose leaks into the engine coolant system. An ultraviolet light must be used to detect the fluorescent dye solution.
Diagnosis by Symptom Index-Directions
The Diagnosis by Symptom Index gives the technician diagnostic information, direction, and suggest possible components, using a symptom as a starting point.
The Diagnosis by Symptom Index is divided into two categories: Electrical Routines, indicated by 200 series numbers, and Hydraulic/Mechanical Routines, indicated by 300 series numbers. The Electrical Routines list the possible electrical components that could cause or contribute to the symptom described. The Hydraulic/Mechanical Routines list the possible hydraulic or mechanical components that could cause or contribute to the symptom described.
1. Using the Symptom Index, select the Concern/Symptom that best describes the condition.
2. Refer to the routine indicated in the Diagnosis by Symptom Index.
3. Always begin diagnosis of a symptom with:
1. Preliminary inspections.
2. Verifications of condition.
3. Checking the fluid levels.
4. Carry outing other test procedures as directed.
4. NOTE: Not all concerns and conditions with electrical components will set a diagnostic trouble code (DTC). Be aware that the components listed may still be the cause. Verify correct function of these components prior to proceeding to the Hydraulic/Mechanical Routine listed.
Begin with the Electrical Routine, if indicated. Follow the reference or action statements. Always carry out the on-board diagnostic tests as necessary. Never skip steps. Repair as necessary. If the concern is still present after electrical diagnosis, then proceed to the Hydraulic/Mechanical Routine listed.
5. The Hydraulic/Mechanical Routines list possible hydraulic or mechanical components that could cause the concern. These components are listed in the removal sequence and by most probable cause. All components listed must be inspected to ensure correct repair.