For 1990-2009 cars

### Diagnostic Aids

The following are the correct switch resistance value range and readings displayed as the cruise control parameters when the switches are pressed one by one in the Body and Accessory/Cruise Control/IPM/Input Data List. If no switch is pressed, the resistance value should be infinite.

Switch Function | Resistance Value Range (Ω) | Counts
--- | --- | ---
Mute/Gap (+) | 1248-1292 | 204-243
Source/Gap (-) | 1537-1591 | 174-203

If there is intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Reference Diagram: Cruise Control Schematics Connector End View Reference: Master Electrical Component List
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Caution: Refer to Fastener Caution in the Preface section.

1. Turn OFF the ignition switch.
2. Disable the inflatable restraint steering wheel module. Refer to SIR Disabling and Enabling.
3. Remove the inflatable restraint steering wheel module. Refer to Steering Wheel Inflatable Restraint Module Replacement
4. Disconnect C277.
5. Turn on the ignition switch, and do not start the engine.
6. Connect a test lamp between the remote radio control head accessory supply voltage circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 10

3 |

1. Turn OFF the ignition switch.
2. With a DMM, measure the resistance between the remote radio control head accessory supply voltage circuit and the adaptive cruise control (ACC) gap adjustment/radio control signal circuit.
3. While measuring the resistance, press and hold the Mute/Gap (+) steering wheel control switch.

Is the resistance measured within the specified value?

1248-1292Ω

Go to Step 4

Go to Step 6

4 | While measuring the resistance, press and hold the Source/Gap (-) steering wheel control switch. Is the resistance measured within the specified value? | -- | Go to Step 5 | Go to Step 9
5 | Test the ACC gap adjustment/radio control signal circuit between C277 and the instrument panel module (IPM) for the following:

• | Short to GND

• | An open circuit

• | High resistance

| Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 8

6 | Test the remote radio control head accessory supply voltage circuit between C277 and the steering wheel control switch for an open or for a high resistance. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 7

7 | Test the ACC gap adjustment/radio control signal circuit between C277 and the steering wheel control switch for the following:

• | Short to GND

• | An open circuit

• | High resistance

Refer to Circuit Testing and Wiring Repairs.

Is the repair complete?

--

Go to Step 13

Go to Step 9

8 | Replace the Cruise Control switch. Refer to Turn Signal Multifunction Switch Replacement. Have you finished the replacement? | -- | Go to Step 10 | --
9 | Inspect for poor connections and terminal tension at the harness connector of the IPM. Refer to Control Module References. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11
10 | Repair the following in the remote radio control head accessory supply voltage circuit:

• | An open circuit

• | Short to GND

• | High resistance

| Refer to Circuit Testing and Wiring Repairs.

Is the repair complete?

--

Go to Step 13

--

11 | Replace the instrument panel module (IPM). Refer to Control Module References. Have you finished the replacement? | -- | Go to Step 13 | --
12 | Replace the steering wheel control switch assembly. Refer to Steering Wheel Control Switch Assembly Replacement. Have you finished the replacement? | -- | Go to Step 13 | --
13 |

1. Install the inflatable restraint steering wheel module. Refer to Steering Wheel Inflatable Restraint Module Replacement.
2. Enable the inflatable restraint steering wheel module. Refer to SIR Disabling and Enabling.
3. Operate the system to verify the repair.

Is the failure removed?

--

Go to Step 2

System OK