A/T - Service Manual Update
87AMCjeep101E452
DECEMBER 1987
1987-88 CHEROKEE/ WAGONEER/COMANCHE
AUTOMATIC TRANSMISSION Attention: Workshop, Parts Department
UPDATE AND REVISION TO T.A. AW-4 COMPONENT SERVICE MANUAL
This I.S. Note contains service information unique to the AW-4 automatic transmission used in 1987-88 CHEROKEE/WAGONEER/COMANCHE models. Only those items that apply to the AW-4 transmission are outlined in this I.S. Note. All other service information in the T.A. AW-4 manual remains unchanged. Service information in the manual affected by these updates/revisions include:
^ Neutral Safety Switch Installation and Adjustment
^ Speed Sensor Testing
^ TPS Test and Adjustment
NEUTRAL SAFETY SWITCH ADJUSTMENT
The neutral safety switch installation and adjustment procedure on pages 42 and 43 of the manual has been updated. Record the update on these pages and refer to the following new procedure.
Switch Installation and Adjustment
1. Disconnect the shift linkage rod from the transmission shift lever The lever is at the left side of the transmission.
2. Rotate the shift lever fully rearward to the Park position. Then rotate the lever forward two detents into the Neutral position.
FIGURE 1:
3. Install the switch (A) on the manual valve shaft (Fig. 1).
4. Install but do not tighten the switch adjusting bolt (B) (Fig. 1).
5. Install the tabbed washer (C) and switch retaining nut (D) on the manual valve shaft (Fig. 1).
6. Tighten the retaining nut to 6.9 N-m (61 in. lbs.) torque but do not bend any of the washer tabs over the nut at this time.
FIGURE 2:
7. Verify that the transmission is still in Neutral.
8. Rotate the switch to align the neutral standard line with the vertical groove on the manual valve shaft (Fig. 2).
9. Tighten the switch adjusting bolt to 13 N-m (9 ft.lbs.) torque (Fig. 2).
FIGURE 1:
10. Secure the switch retaining nut by bending at least two of the washer tabs (C) over the nut (Fig. 1).
11. Connect the shift linkage rod to the transmission shift lever.
SPEED SENSOR TESTING
The speed sensor testing procedure on pages 56 and 57 of the manual has been updated. The update applies to 1988 models. Record the update on these pages and refer to the following new procedure.
FIGURE 3:
Speed Sensor Testing
The connector on the 1988 sensor now has two terminals which requires a change in the ohmmeter test hookup.
1. To check continuity on the 1988 sensor place the ohmmeter test leads on the two terminals in the sensor connector (A) as shown in Figure 3.
2. Rotate the transmission output shaft and observe the ohmmeter needle.
3. The meter needle should deflect indicating the switch is opening/closing as the rotor (B) on the output shaft moves past the sensor switch (C) (Fig. 3).
NOTE: If a digital ohmmeter is being used to test the sensor, the sensor should generate a readout each time the sensor switch opens and closes.
4. Replace the sensor (D) if the ohmmeter does not display any type of reading.
THROTTLE POSITION SENSOR (TPS) TEST AND ADJUSTMENT PROCEDURES
The TPS test and adjustment procedures on pages 58, 59 and 60 have been revised. Record this I.S. Note on the indicated pages and refer to the following revised test and adjustment procedures.
FIGURE 4:
TPS Location and Type
The TPS is attached to the base of the throttle body on 2.5L and 4.0L engines.
Two TPS styles are used. Style (1) is used on 4.0L engines. Style (2) is used on 2.5L engines (Fig. 4).
FIGURE 5:
TPS Connector
TPS input/output voltage is checked at the square, four-terminal, two-piece connector (3) (Fig. 5).
If diagnosis indicates a loose or corroded connection, release the lock tab and separate the two halves of the connector. Inspect and clean the connector terminals if dirty or corroded.
Be sure the connector halves are fully seated before engaging the lock tab. This is necessary to ensure a good connection.
FIGURE 6:
Testing TPS Operation
A voltmeter is used to test the TPS. Operation is checked by measuring input and output voltage at the TPS connector terminals.
The connector terminals are identified by the letters A, B, C, D molded into the back of the connector (Fig. 6).
Testing Input Voltage
1. Turn the ignition key to the On position.
2. Connect the voltmeter negative lead to terminal D.
NOTE: To contact the connector terminal, insert the voltmeter test lead from the back of the connector. Insert the lead between the wire and rubber seal to contact the terminal.
3. Connect the voltmeter positive lead to terminal A.
4. Close the throttle plate completely. Be sure the throttle lever is seated against the idle stop.
5. Note input voltage. Voltage at terminals A and D should be approximately 5.0 volts on both four and six-cylinder engines.
6. Leave the voltmeter leads in place and proceed to the output voltage test.
Testing Output Voltage
1. Remove the voltmeter positive lead from terminal A and connect it to terminal B.
2. On four-cylinder engines, move the throttle plate to the wide open position and note output voltage. Output voltage should be 4% of input voltage (approximately 0.2 volts).
3. On six-cylinder engines, hold the throttle plate closed and note output voltage. Voltage should be 82% of input voltage (approximately 4.2 volts).
4. If output voltage is not within the specified range, leave the voltmeter connected and proceed to TPS adjustment.
FILING INSTRUCTIONS
File this I.S. Note in the T.A. AW-4 manual.
TPS Adjustment
The TPS can be adjusted with either a voltmeter or with the MS 1700 tester. Adjustment with the MS 1700 tester is the preferred method.
1. Loosen the TPS attaching screws. Then partially tighten one of the screws to secure the sensor for adjustment.
2. If a voltmeter is used for adjustment, connect the positive lead to terminal B and the negative lead to terminal D.
3. If the MS 1700 tester is used for adjustment, connect the tester as outlined in the tester manual.
4. Observe the voltmeter/tester and rotate the sensor until specified output voltage is obtained.
5. Tighten the sensor attaching screws and verify adjustment.