Initial Inspection and Diagnostic Overview
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 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
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.
correct linkage adjustments
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.
After carrying out the Quick Test, use the Transmission Drive Cycle Test for checking continuous codes.
1. Record and then erase Quick 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 Quick 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.