Test Procedures
If cruise control does not work properly, refer to CRUISE SYSTEM TEST. If cruise indicator does not work properly, but all other cruise functions work properly, refer to CRUISE INDICATOR TEST.
When performing the following tests, refer to wiring diagrams and connector pin locations under, Cruise Control/Diagrams/Electrical.
CRUISE SYSTEM TEST
Fig. 3 Connector C235 Pin Locations:
1. Turn ignition switch to Run position, place cruise switch in On position and connect test lamp to connector C235 Fig. 3, as follows:
a. Connect between terminal A (brown/white wire) and ground. If lamp does not illuminate on 1989 6000 or Celebrity check Gages or Radio fuse, pink/black wire (circuit 39), yellow wire (circuit 43, 1990 6000 and Celebrity) and brown/white wire (circuit 141) for an open.
b. Connect between terminal B (gray wire) and ground. If lamp does not illuminate, replace multi-function lever.
c. Place cruise switch in Resume/Accel position.
d. Connect between terminal B (gray wire) and ground. If lamp does not illuminate, replace multi-function lever.
e. Connect between terminal C (gray/black wire) and ground. If lamp does not illuminate, replace multi-function lever.
f. Release cruise switch to On position.
g. Connect between terminal C (gray/black wire) and ground. If lamp illuminates, replace multi-function lever.
h. Connect between terminal D (dark blue wire) and ground. If lamp illuminates, replace multi-function lever.
i. Press set switch, connect between terminal D (dark blue wire) and ground. If lamp does not illuminate, replace multi-function lever.
Fig. 2 ECM Connector Pin Locations:
2. If lamp illuminated in steps a, b, d, e, and i, and did not illuminate in steps g and h, turn off ignition, disconnect ECM connectors C1 and C2 Fig. 2, turn ignition switch to Run position, place cruise control switch in On position and measure voltage between terminals as follows:
a. Measure between terminal C2/20 (gray wire) and ground. If battery voltage is not available, check gray wire (circuit 397) for an open.
b. Measure between terminal C1/14 (brown wire, 6000 and Celebrity) and ground. If battery voltage is not available on 6000 or Celebrity, check brake switch, adjusting as necessary, and check brown wire (circuit 86) for an open.
c. Press set switch and measure between terminal C2/21 (dark blue wire) and ground. If battery voltage is not available, check dark blue wire, circuit 84) for an open.
d. Release set switch, place cruise switch in Resume/Accel position and measure between terminal C2/4 (gray/black wire) and ground. If battery voltage is not available, check gray black wire (circuit 87) for an open.
3. If battery voltage is available in steps a through d, and voltage pulses approximately battery voltage and less than 7 volts in step e, disconnect ECM connectors C1 and C2 Fig. 2, and measure resistance as follows:
a. Measure between terminal C1/10 and ground. If resistance is not 30-55 ohms, check cruise control servo, light green wire (circuit 402) and black wire (circuit 150).
b. Measure between terminal C1/11 (dark blue/white wire) and ground. If resistance is not 30-55 ohms, check cruise control servo and dark blue/white wire (circuit 403).
c. On vehicles with automatic transaxle, place gearshift in Neutral and measure between terminal C2/18 (orange/black wire, 6000 and Celebrity) and ground. If resistance is not 0 ohms on 6000 and Celebrity, check automatic transaxle selector switch and orange/black wire (circuit 434) for an open.
d. Place gearshift in Drive and measure between terminal C2/18 (orange/black wire, 6000 and Celebrity) and ground. If reading is not infinity on 6000 and Celebrity, check automatic transaxle selector switch and orange/black wire (circuit 434) for a short to ground.
4. If resistance was 30-55 ohms in steps a and b, 0 ohms in step c and infinite ohms in step d, disconnect cruise control servo, jumper terminal C of servo to ground, jumper terminal A of servo to battery, run engine for 1 minute then turn off and proceed as follows:
a. Connect fused jumper between terminal E of cruise control servo and ground. If vacuum does not pull servo all the way in, check for blocked or leaking vacuum source and, if vacuum source is satisfactory, plug vacuum release port and repeat step 4. If vacuum now pulls servo all the way in, repair or replace vacuum release valve or the hose to it. If test still fails, replace cruise control servo.
b. Remove fused jumper. If vacuum does not hold servo all the way in, check for blocked or leaking vacuum source and, if vacuum source is satisfactory, plug vacuum release port and repeat step 4. If vacuum now holds servo all the way in, repair or replace vacuum release valve or the hose to it. If test still fails, replace cruise control servo.
c. If vacuum pulls servo all the way in in step a and holds servo all the way in in step b, replace ECM.
CRUISE INDICATOR TEST
1. Disconnect ECM connector C1 Fig. 2, turn ignition switch to Run position and connect fused jumper between terminal 18 (white wire) and ground.
2. If cruise indicator lights, replace ECM.
3. If cruise indicator does not light, check bulb and wiring.