DTC P0581: Speed Control Switch #1 High: Testing
- DO NOT press any S/C Switches. Turn the ignition on, with the engine off. With the DRBIII(R), read the S/C voltage. Is the S/C voltage more than 4.8 volts? If yes, go to next step. If no, see INTERMITTENT FAILURES under ON-BOARD DIAGNOSTICS. If no, go to next step.
- Turn the ignition off. Remove the S/C Switches from the steering wheel. Measure the resistance across each S/C Switch (component side). Monitor the ohmmeter while pressing each function button on each switch. Does the function on the S/C Switches have the correct resistance value? See SPEED CONTROL SWITCH RESISTANCE SPECIFICATIONS
table. If yes, go to next step. If no, replace the S/C Switch that has the incorrect resistance value.SPEED CONTROL SWITCH RESISTANCE SPECIFICATIONS
Application Ohms Cancel 900-918 Coast (Decel) 2910-2970 On/Off Zero Resume/Accel 15,400 Set 6584-6716 - Disconnect the PCM harness connectors. Measure the voltage on the S/C Switch Signal circuit in each S/C Switch harness connector. Is the voltage more than 5.0 volts? If yes, repair the short to battery voltage in the S/C Signal circuit. If no, go to next step.
- Measure the resistance of the S/C Switch Signal circuit from each S/C Switch harness connector to the appropriate terminal in the Miller Special Tool. Is the resistance less than 5.0 ohms? If yes, check the PCM harness connector terminals for corrosion, damage, or terminal push-out. Repair as necessary. If PCM harness connectors are okay, replace the PCM. If no, repair the open in the Sensor Ground circuit.
WARNING:
Deactivate air bag system before performing any service operation. See appropriate AIR BAG RESTRAINT SYSTEMS article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
CAUTION:
DO NOT probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Install Miller Special Tool (8815) to perform diagnosis.