Cruise Control Will Not Engage

Turn ignition off. Disconnect cruise control module connector. Turn ignition on (engine off). Connect test light between connector terminal "F" (Pink wire) and ground. See Fig 1 . If test light glows, go to next step. If test light does not glow, check GAUGES fuse (10-amp). Replace as necessary. If fuse is okay, repair poor connection or open circuit in Pink wire.

Fig 1: Cruise Control Module Connector Terminal ID (Century & Ciera)
Courtesy of GENERAL MOTORS CORP.
Connect test light between cruise control module connector terminals "F" (Pink wire) and "E" (Black wire). If test light glows, go to next step. If test light does not glow, repair poor connection or open circuit in Black wire.
Turn cruise control on. Connect test light between cruise control module connector terminals "E" (Black wire) and "A" (Gray wire). If test light glows, go to step 6). If test light does not glow, go to next step.
Connect test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). While observing test light, press and hold SET/COAST switch. If test light does not glow, go to next step. If test light glows, check for a poor connection, short to ground or open in Gray wire between cruise control module and multifunction lever. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Check GAUGES fuse (10-amp). Replace as necessary. If fuse is okay, check for a poor connection or open in Pink wire between multifunction lever and fuse block. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Connect test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). While observing test light, press and hold SET/COAST switch. If test light glows, go to next step. If test light does not glow, check for a poor connection, short to ground or open in Dark Blue wire between cruise control module and multifunction lever. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Connect test light between cruise control module connector terminals "E" (Black wire) and "C" (Gray/Black wire). While observing test light, press and hold SET/COAST switch. If test light does not glow, go to next step. If test light glows, check Gray/Black wire for a short to Dark Blue wire. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Connect test light between cruise control module connector terminals "E" (Black wire) and "D" (Purple wire). If test light glows, go to step 10). If test light does not glow, go to next step.
Backprobe with a test light between cruise control brake (release) switch connector terminal "B" (Purple wire) and ground. If test light glows, repair poor connection or open in Purple wire between brake switch, cruise control module and PCM. If test light does not glow, check for a poor connection or open circuit in Brown wire between brake switch and fuse block. If circuit is okay, check cruise control brake switch for correct alignment. If alignment is okay, replace switch.
Connect test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). If test light does not glow, go to next step. If test light glows, check for a short to power in Dark Blue wire. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Connect test light between cruise control module connector terminals "E" (Black wire) and "C" (Gray/Black wire). If test light does not glow, go to next step. If test light glows, check for a short to power in Gray/Black wire. If circuit is okay, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article.
Check for a poor connection or open in Dark Green wire between cruise control module and PCM. If circuit is okay, replace cruise control module. See CRUISE CONTROL MODULE under REMOVAL & INSTALLATION.