A/T - 4EAT No 3-4 Upshift/No 2-1 Downshift

Article No.
92-18A-3

09/04/92

^ LAMP - MANUAL SHIFT LIGHT DISPLAYED INTERMITTENTLY - 4EAT TRANSAXLE

^ TRANSAXLE - 4EAT - MANUAL SHIFT LIGHT DISPLAYED INTERMITTENTLY

^ TRANSAXLE - 4EAT - NO 3-4 UPSHIFT OR 2-1 DOWNSHIFT

FORD:
1989-90 PROBE

This TSB article is being republished in its entirety to correct the first note in the article. A 4-3 downshift will occur when the manual shift light is on.

ISSUE:
An intermittent display of the manual shift light may be caused by a faulty transaxle pulse signal generator. The 4EAT electronic controller may store a memory code 55. Also, if the manual shift light flashes or stays on while driving, the transaxle may respond as follows:

^ No 3-4 upshift

^ No 2-1 downshift

ACTION:
Inspect the pulse signal generator to determine if replacement is required. Refer to the following procedure for service details.

1. Road test the vehicle to check the operation of the manual shift button and light.

NOTE:
THE MANUAL SHIFT LIGHT MUST TURN ON WHEN THE MANUAL SHIFT BUTTON IS DEPRESSED. THIS WILL ALLOW A 4-3 DOWNSHIFT. IF THE MANUAL SHIFT LIGHT TURNS ON WHILE IN 4TH GEAR, WITHOUT DEPRESSING THE MANUAL SHIFT BUTTON, OR FLASHES INTERMITTENTLY, PROCEED TO STEP # 2.

2. Perform the 4EAT Self Test before disconnecting the transmission controller. Use one of the following methods.

USING SUPER STAR II TESTER

^ Turn the ignition key off.

^ Connect the MECS adapter cable to the star tester.

^ Connect the adapter cable leads to the blue 4EAT STO and STI connectors. (Located under the dash on the left side of the steering shaft).

^ Ground the adapter cable.

^ Position the star tester switch to the MECS position.

^ Latch the center button in the test position.

^ Turn the ignition key on.

^ Turn the star tester on. It will sound and display an "888" for two seconds.

^ Unlatch and relatch the center test button.

^ Record codes, then unlatch the center button. Refer to the 1989 Probe Shop Manual, page 17-01-15 for the Service Code Chart and Troubleshooting Guide.

USING AN ANALOG VOLTMETER

^ Connect a jumper wire from the 4EAT STI lead to ground.

^ Connect the VOM positive lead to the 4EAT STO wire. For 1990 vehicles use the Engine Emissions Diagnosis (non-NAAO) Shop Manual, page 15-5. For 1989 vehicles use the 1989 Probe Shop Manual, page 17-01-14.

^ Connect the VOM negative lead to ground.

^ Set the VOM to the 20 volt range.

^ Turn the ignition key on.

^ Disconnect and reconnect the STI jumper to ground.

^ Observe the VOM needle for any code indications. Refer to the 1989 Probe Shop Manual, page 17-01-15 for the Service Code Chart and Troubleshooting Guide.

USING "MANUAL SHIFT LIGHT (MSL)"

^ Turn the ignition key on.

^ Jumper the 4EAT STI wire to ground.

^ Observe the MSL light for blinking.

^ Record codes. Refer to the 1989 Probe Shop Manual, page 17-01-15 for the Service Code Chart and Troubleshooting Guide.

NOTE:
DISCONNECTING THE CONTROLLER WILL ERASE ANY CODES STORED IN MEMORY. A CODE "55" DISPLAYED ON THE VOM OR SUPER STAR II IS AN INDICATION OF A FAULTY PULSE SIGNAL GENERATOR, OR WIRE HARNESS BETWEEN THE MANUAL SHIFT BUTTON AND CONTROLLER, OR HARNESS TO THE PULSE SIGNAL GENERATOR.

3. If a code "55" was displayed, refer to the 1989/90 Probe Shop Manual, page 17-01-25 and proceed as follows:

a. Perform Pin Point Test PPC1-PPC3.

b. While measuring the resistance, wiggle the wire harness near the pulse signal generator.

c. Replace the signal generator if the resistance value is above or below 200-400 ohms. Refer to the 1989/90 Probe Shop Manual for service details. Tighten pulse generator 69-95 lb-in (8-11 N-m).

4. If the resistance values obtained in Step # 3 are between 200-400 ohms and the harness passed the wiggle test, inspect and repair the wiring from the manual shift button controller to the signal generator.

5. After repairs are performed, road test the vehicle and check for proper operation of the manual shift light.

PART NUMBER PART NAME CLASS

E92Z-7F040-A Pulse Signal Generator C

OTHER APPLICABLE ARTICLES: 90-4-8
SUPERSEDES: 90-1-6
WARRANTY STATUS:
Eligible Under Basic Warranty Coverage

OPERATION DESCRIPTION TIME
928A03A Diagnose & Install Pulse 1.1 Hrs.
Signal Generator
928A03B Diagnose & Repair Wiring 1.3 Hrs.

DEALER CODING
BASIC PART NO. CONDITION CODE
7F040 42

OASIS CODES: 204000, 501000, 502000, 503000