Diagnosis And Testing - Speed Control Switch
To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the SRS. Failure to take the proper precautions could result in accidental airbag deployment.
The following test confirms only correct speed control switch functions. It does not test or confirm any of the Local Interface Network (LIN) slave node inputs, outputs or functions. LIN slave node testing requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
- Remove the speed control switch pod from the steering wheel. Refer to SWITCH, SPEED CONTROL, REMOVAL .
- Disconnect the steering wheel wire harness connector from the back of the speed control switch pod.
- Using an ohmmeter, test the resistance between the terminals of the switch as shown in the Speed Control Switch Tests table below.
SPEED CONTROL SWITCH TESTS SWITCH POSITION PINS (*RESISTANCE - OHMS) NO PUSH BUTTONS DEPRESSED 13 and 14 (20708)
14 and 15 (20591)ON/OFF 13 and 14 (464)
14 and 15 (133)CANCEL 13 and 14 (896)
14 and 15 (457)DISTANCE (WITH ADAPTIVE SPEED CONTROL ONLY) 13 and 14 (1515)
14 and 15 (899)MODE (WITH ADAPTIVE SPEED CONTROL ONLY) 13 and 14 (2468)
14 and 15 (1518)SET /- (DECEL) 13 and 14 (4088)
14 and 15 (2471)RESUME /+ (ACCEL) 13 and 14 (7408)
14 and 15 (4091)*All resistance values are plus or minus 5%. - If the switch fails any of the tests, replace the ineffective speed control switch pod as required.