GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Seville 🢒 Body and Accessories 🢒 Cruise Control 🢒 Cruise Control Inoperative

Step

Action

Value(s)

Yes

No

1

Was the Cruise Control System Check performed?

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Go to Step 2

Go to Cruise Control System Check

2
  1. Connect a scan tool to the data link connector (DLC).
  2. Turn ignition ON.
  3. Select powertrain control module (PCM) on the scan tool.
  4. Check for PCM DTCs. (In particular note if cruise control related DTCs P1554, P1560, P1564, P1566, P1567, P1570 or P1654 are set.)

Are any PCM DTCs set?

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Go to Step 3

Go to Step 4

3

Diagnose the PCM DTCs. Refer to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.6L.

Is the repair complete?

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Go to Step 46

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4

Check for open CR CONT fuse in the underhood junction block.

Is the fuse open?

--

Go to Step 5

Go to Step 6

5

Repair short to ground on CKT 639 (PNK).

Is the circuit repair complete?

--

Go to Step 46

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6
  1. Turn ignition to ON.
  2. Using the scan tool, select PCM.
  3. Select engine data list and monitor the TCC brake switch input.
  4. Depress and release the brake pedal.

Does the TCC brake switch input, displayed on the scan tool, change from Released to Applied and back?

--

Go to Step 7

Go to Step 19

7
  1. Turn ignition switch to OFF.
  2. Disconnect the cruise control module connector.
  3. Turn ignition switch to ON.
  4. Connect a DMM between cruise control module connector terminal F and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 9

Go to Step 8

8

Repair open in CKT 639 (PNK).

Is the circuit repair complete?

--

Go to Step 46

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9

Connect a DMM between cruise control module connector terminal E and battery positive voltage (B+).

Is the voltage within the specified range?

10-15 V

Go to Step 11

Go to Step 10

10

Repair open in CKT 150 (BLK).

Is the circuit repair complete?

--

Go to Step 46

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11
  1. Turn cruise control switch to ON.
  2. Connect a DMM between cruise control module terminal A and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 18

Go to Step 12

12

Check for open fuse IGN1 in the rear junction block.

Is the fuse open?

--

Go to Step 13

Go to Step 14

13

Repair short to ground on CKT 1039 (PNK).

Is the circuit repair complete?

--

Go to Step 46

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14
  1. Turn ignition to OFF.
  2. Disconnect the cruise control switch connector.
  3. Turn ignition to ON.
  4. Connect a DMM between cruise control switch connector terminal B and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 16

Go to Step 15

15

Repair open in CKT 1039 (PNK).

Is the circuit repair complete?

--

Go to Step 46

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16
  1. Turn ignition to OFF.
  2. Connect a fused jumper across cruise control switch connector terminals A and B.
  3. Turn ignition to ON.
  4. Connect a DMM between cruise control module connector terminal A and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 33

Go to Step 17

17

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

Is the circuit repair complete?

--

Go to Step 46

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18
  1. Turn ignition to ON.
  2. Connect a DMM between the cruise control module connector terminal D and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 27

Go to Step 23

19
  1. Turn ignition to OFF.
  2. Disconnect the ABS/TCC switch connector.
  3. Turn ignition to ON.
  4. Connect a DMM between ABS/TCC switch connector terminal A and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 21

Go to Step 20

20

Repair open CKT 1039 (PNK).

Is the circuit repair complete?

--

Go to Step 46

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21
  1. Turn ignition to OFF.
  2. Connect a fused jumper across ABS/TCC switch terminals A and B.
  3. Turn ignition to ON.
  4. Connect a DMM between cruise control module terminal D and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 22

Go to Step 23

22

Check ABS/TCC switch connector for poor terminal contact. If OK, replace the ABS/TCC switch. Refer to Cruise Control Release Switch Replacement .

Is the replacement complete?

--

Go to Step 46

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23
  1. Turn ignition to OFF.
  2. Reconnect the ABS/TCC switch connector if previously disconnected.
  3. Disconnect the cruise control switch connector.
  4. Turn ignition to ON.
  5. Connect a DMM between cruise control switch connector terminal E and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 25

Go to Step 24

24

Repair open CKT 420 (PPL).

Is circuit repair complete?

--

Go to Step 46

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25
  1. Turn ignition to OFF.
  2. Connect a fused jumper across cruise control switch connector terminals E and F.
  3. Turn ignition to ON.
  4. Connect a DMM between cruise control module connector terminal D and ground.

Is the voltage within the specified range?

10-15 V

Go to Step 33

Go to Step 26

26

Repair open CKT 696 (LT GRN).

Is the circuit repair complete?

--

Go to Step 46

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27
  1. Connect a DMM between the cruise control module connector terminal B and ground.
  2. Depress and hold the SET/COAST switch.

Is the voltage within the specified range?

10-15 V

Go to Step 30

Go to Step 28

28

Check for open or short to ground in CKT 84 (DK BLU).

Is the circuit OK?

--

Go to Step 33

Go to Step 29

29

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

Is the circuit repair complete?

--

Go to Step 46

--

30
  1. Connect a DMM between cruise control switch connector terminal C and ground.
  2. Depress the SET/COAST switch.

Is the voltage within the specified range?

10-15 V

Go to Step 34

Go to Step 31

31

Check for an open or a short in CKT 84 (DK BLU).

Is the circuit OK?

--

Go to Step 33

Go to Step 32

32

Repair open CKT 84 (DK BLU).

Is the circuit repair complete?

--

Go to Step 46

--

33
  1. Check the cruise control switch connector for poor terminal contact.
  2. If OK, replace the cruise control switch. Refer to Cruise Control Switch Assembly - Pivot and Pulse in Steering Wheel and Column - Tilt.

Is the replacement complete?

--

Go to Step 46

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34

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

Is the voltage within the specified range?

10-15 V

Go to Step 35

Go to Step 36

35

Repair short to voltage on CKT 17 (WHT).

Is the circuit repair complete?

--

Go to Step 46

--

36

Connect a DMM set to ohms scale between cruise control module terminals B and C.

Does the DMM indicate an open circuit (OL) exists between the two terminals?

OL

Go to Step 38

Go to Step 37

37

Repair short between CKT 87 (GRY/BLK) and CKT 84 (DK BLU).

Is the circuit repair complete?

--

Go to Step 46

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38
  1. Set the park brake.
  2. Raise the drive wheels.
  3. Connect a DMM set to ac voltage scale to the cruise control module connector terminal K.
  4. Rotate the drive wheels by hand and observe the DMM.

Does the voltage vary?

--

Go to Step 40

Go to Step 39

39

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

Is the circuit repair complete?

--

Go to Step 46

--

40
  1. Turn the ignition to OFF.
  2. Reinstall the cruise control module connector.
  3. Connect a scan tool to the data link connector (DLC).
  4. With the drive wheels raised, start the engine and bring the vehicle speed above 25 MPH.
  5. Clear all DTCs.
  6. Using the scan tool, select PCM, and select Eng 3 data list. Monitor the cruise enable driver output displayed on the scan tool.
  7. Attempt to operate the cruise control.

Does the scan tool display cruise enable driver OK?

--

Go to Step 41

Go to Step 42

41

Diagnose the powertrain control module (PCM). Refer to Powertrain On Board Diagnostic (OBD) System Check .

Is the repair complete?

--

Go to Step 46

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42
  1. Turn the ignition switch to OFF.
  2. Disconnect the powertrain control module (PCM) connector C1.
  3. Connect a DMM from PCM connector C1 terminal 26 and ground.
  4. Turn the ignition switch to ON.

Is the voltage within the specified range?

10 - 15V

Go to Step 44

Go to Step 43

43

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

Is the circuit OK?

--

Go to Step 44

Go to Step 45

44
  1. Check cruise control module connector for poor terminal contact.
  2. If OK, replace the cruise control module. Refer to Cruise Control Module Replacement .

Is the replacement complete?

--

Go to Step 46

--

45

Repair CKT 83 (DK GRN).

Is the circuit repair complete?

--

Go to Step 46

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46
  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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