GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Body and Accessories 🢒 Cruise Control 🢒 Cruise Control Inoperative

Step

Action

Value(s)

Yes

No

1

Did you perform the Cruise Control System Check ?

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Go to Step 2

Go to Cruise Control System Check

2
  1. Turn the cruise switch to OFF.
  2. Disconnect the cruise control module connector.
  3. Turn the ignition switch to RUN.
  4. Connect a J 39200 digital multimeter (DMM) between terminal F of the cruise control module connector and ground.

Is the measured voltage in the specified range?

10-15V

Go to Step 4

Go to Step 3

3

Repair the open in CKT 339 (PNK).

Is the repair complete?

--

Go to Step 31

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4

Connect a DMM between terminal F and terminal E of the cruise control module connector.

Is the measured voltage in the specified range?

10-15V

Go to Step 6

Go to Step 5

5

Repair the open in CKT 451 (BLK/WHT).

Is the repair complete?

--

Go to Step 31

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6

Connect a DMM between terminal E1 of connector C202 and ground.

Is the measured voltage in the specified range?

10-15V

Go to Step 8

Go to Step 7

7

Repair the open in CKT 1039 (PNK).

Is the repair complete?

--

Go to Step 31

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8
  1. Turn the cruise switch to ON.
  2. Connect a DMM between terminal E2 of connector C202 and ground.

Is the measured voltage in the specified range?

10-15V

Go to Step 10

Go to Step 9

9
  1. Check the multifunction lever connector for poor terminal contact.
  2. If OK, replace the multifunction lever. Refer to Turn Signal and Multifunction Switch Assembly - Disassemble - Off Vehicle and Turn Signal and Multifunction Switch Assembly - Assemble - Off Vehicle in Steering Wheel and Column - Tilt.

Is the repair complete?

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Go to Step 31

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10

Connect a DMM between terminal A of the cruise control module connector and ground.

Is the measured voltage in the specified range?

10-15V

Go to Step 12

Go to Step 11

11

Repair the short to ground or open in CKT 397 (GRY).

Is the repair complete?

--

Go to Step 31

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12
  1. Connect a DMM between terminal E3 of the connector C202 and ground.
  2. Press and hold the SET button.

Is the measured voltage in the specified range?

10-15V

Go to Step 13

Go to Step 9

13
  1. Connect a DMM between terminal B of the cruise control module connector and ground.
  2. Press and hold the SET button.

Is the measured voltage in the specified range?

10-15V

Go to Step 15

Go to Step 14

14

Repair the short to ground or open in CKT 84 (DK BLU).

Is the repair complete?

--

Go to Step 31

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15

Connect a DMM between terminal G of the cruise control module connector and ground.

Is the measured voltage in the specified range?

Above 0.5V

Go to Step 16

Go to Step 17

16

Repair CKT 20 (LT BLU) for the short to battery positive voltage (B+).

Is the repair complete?

--

Go to Step 31

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17
  1. Connect a DMM between terminal D of the cruise control module connector and ground.
  2. Press the brake pedal, then release the pedal.

Is the measured voltage less than 0.5 volts with the pedal depressed and in the specified range with the pedal released?

10-15V

Go to Step 23

Go to Step 18

18
  1. Turn the ignition switch to OFF.
  2. Disconnect the ABS/TCC switch connector.
  3. Connect a DMM between ABS/TCC switch connector terminal A and ground.
  4. Turn the ignition switch to RUN.

Is the measured voltage in the specified range?

10-15V

Go to Step 20

Go to Step 19

19

Repair short to ground or open in CKT 1039 (PNK).

Is the repair complete?

--

Go to Step 31

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20
  1. Turn the ignition switch to OFF.
  2. Connect a fused jumper across ABS/TCC switch connector terminals A and B.
  3. Connect a DMM between cruise control module connector terminal D and ground.
  4. Turn the ignition switch to RUN.

Is the measured voltage within the specified range with the jumper connected and less than 0.5 volts with the jumper removed?

10-15V

Go to Step 22

Go to Step 21

21

Repair the open, short to ground or short to battery positive voltage (B+) in CKT 420 (PPL).

Is the repair complete?

--

Go to Step 31

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22
  1. Check the ABS/TCC switch connector for poor terminal contact.
  2. If OK, replace the ABS/TCC switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

--

Go to Step 31

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23
  1. Set the park brake.
  2. Raise the drive wheels.
  3. Using a DMM, measure the voltage between cruise control module connector terminal K and ground.
  4. While observing the display of the DMM, rotate the drive wheels by hand.

Does the voltage vary?

--

Go to Step 25

Go to Step 24

24

Repair the open in CKT 817 (DK GRN/WHT).

Is the repair complete?

--

Go to Step 31

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25
  1. Turn the ignition switch to OFF.
  2. Reconnect the cruise control module.
  3. Disconnect the powertrain control module (PCM) connector C1.
  4. Connect a DMM from PCM connector C1 terminal 26 to ground.
  5. Turn the ignition switch to RUN.

Is the measured voltage within the specified range?

10-15V

Go to Step 28

Go to Step 26

26

Check CKT 83 (DK GRN) for an open or short to ground.

Is the circuit OK?

--

Go to Step 29

Go to Step 27

27

Repair open or short to ground in CKT 83 (DK GRN).

Is the repair complete?

--

Go to Step 31

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28
  1. Turn the ignition switch to OFF.
  2. Reconnect the PCM connector C1.
  3. Disconnect the cruise control module connector.
  4. Turn the ignition switch to RUN.
  5. Using the scan tool, clear all the DTCs.
  6. Using the scan tool, select PCM, Special Functions, Engine Output Controls.
  7. Select Cruise Inhibit and command the PCM to turn cruise inhibit off.
  8. Using a DMM, measure the voltage from the cruise control module connector terminal H to ground.

Is the measured voltage within the specified range with Cruise Inhibit off (NO), and less than 0.5 volts with Cruise Inhibit on (YES)?

10-15V

Go to Step 30

Go to Step 29

29
  1. Check the cruise control module connector for poor terminal contact.
  2. If OK, replace the cruise control module. Refer to Cruise Control Module Replacement .

Is the repair complete?

--

Go to Step 31

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30

Diagnose the powertrain control module (PCM). Refer to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls--4.6L.

Is the repair complete?

--

Go to Step 31

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31
  1. Make sure any components removed during diagnosis are installed in place and that all connectors are connected.
  2. Repeat the system check. Refer to Cruise Control System Check .

Is the system check complete?

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System OK

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