For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: This diagnostic table is used to diagnose the following cruise control features that are inoperative from the cruise control switch only:

• | cruise control does not resume to preset speed

• | decel to a desired lower speed

• | accelerate to a desired faster speed

• | increase speed in small amounts (tap up)

• | decrease speed in small amounts (tap down)

1 | Did you perform the Cruise Control System Check? | -- | Go to Step 2 | Go to Cruise Control System Check
2 | Is the customer complaint one of the following:

• | Cruise Control Does Not Resume

• | Decel

• | Tap Down

--

Go to Step 3

Go to Step 4

3 |

1. Install a scan tool.
2. Establish communication with the engine control module (ECM).
3. With the scan tool, observe the RESUME SWITCH parameter in the ECM data list.
4. Press the RESUME/DECEL button at the end of the lever.

Does the scan tool display ON?

--

Go to Step 5

Go to Step 6

4 | Is the customer complaint Cruise Control Does Not Accelerate or Tap Up when using the switch? | -- | Go to Step 7 | --
5 | Replace the ECM. Is the replacement complete? | -- | Go to Step 8 | --
6 |

1. Turn OFF the ignition.
2. Disconnect ECM connector C2.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage at ECM connector terminal 10 with the RESUME/DECEL button at the end of the lever pressed.

Does the voltage measure within the specified range?

10-12 V

Go to Step 5

Go to Step 9

7 | Replace the cruise control switch. Is the replacement complete? | -- | Go to Step 8 | --
8 | Verify that the cruise control system operates properly. Does the cruise control system operate properly? | -- | System OK | --
9 | Test CKT FX500 for an open circuit. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7