CODE 54 XX -- ONCOMING SPEED TEST (AFTER SHIFT)

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

CODE 54 XX -- ONCOMING SPEED TEST (AFTER SHIFT)

Active Indicator Clearing Procedure:

Power down

Manual

NOTE:

Before troubleshooting, read Paragraph 56. Also, check battery and ECU input voltages.

NOTE:

Intermittent connections or lack of battery-direct power and ground connections may cause this and

other codes.

Troubleshooting:

1. After the transmission is at operating temperature, allow the vehicle to idle on level ground for

34 minutes. Check transmission fluid level. If improper fluid level is found, correct as necessary.

Improper fluid level could be the cause of the code (not enough or too much fluid may produce

inadequate clutch pressure).

2. Connect a pressure gauge and check main pressure. If pressure is not adequate, the pump is

possibly worn. See Appendix B for main pressure specifications.

3. If the fluid level is correct, check the turbine and output speed sensors for accurate, steady signals

using the diagnostic tool (check with vehicle stopped and in range to confirm a zero speed reading

from the turbine and output speed sensors). Check the wiring for opens and shorts (refer to code

22 XX) and the sensor coils for proper resistance. If problems are found, repair or replace as

necessary. Remove speed sensor and check for loose tone wheel.

4. If sensor and wiring resistance are acceptable, connect a pressure gauge(s) to the pressure tap for

the oncoming clutches indicated by the subcode (refer to solenoid and clutch chart in Appendix C).

Make the shift indicated by the code by operating the vehicle or by using the diagnostic tool's

clutch test mode.

5. If the clutch pressure does not show on the gauge(s), the control module is probably not

commanding the clutch on. Drain the fluid and remove the control module. Disassemble and clean

the control module, inspect for stuck or sticking valves.

6. Internal leakage is indicated by the clutch pressure gauge showing that pressure is being sent to the

clutch but the clutch fails to hold. The fault may be: missing or damaged face seals, burnt clutch,

leaking piston sealrings, or damaged control module gaskets. Drain the fluid, remove the control

module, and inspect the face seals and control module gaskets. If the seals and gaskets are

satisfactory, replace the solenoid(s) indicated by the code. If replacing the solenoid does not

eliminate the code, remove the transmission and repair as necessary.

7. If clutch pressures are correct and the clutch appears to be holding, replace the output and turbine

speed sensors.

8. If the problem recurs, use the diagnostic tool to check the speed sensor signals for erratic readings.

Possible causes of erratic speed readings are: loose sensors, intermittent contact in the wiring,

vehicle-induced vibrations, or speed sensor wiring that is not a properly twisted-pair. If necessary,

use a twisted-pair for a new speed sensor circuit -- Service Harness Twisted Pair P/N 200153 is

available from St. Clair Technologies for this purpose.

9. If the condition persists, replace the ECU. If replacing the ECU corrects the problem, reinstall the

original (bad) ECU to confirm that the problem is in the ECU. If the original ECU now works,

inspect the ECU connectors for any corrosion or damage which may cause an intermittent

condition. If the original problem recurs, reinstall the replacement ECU.

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