No Response From CAB
NOTE:
After making any repairs, perform ANTI-LOCK BRAKE SYSTEM VERIFICATION TEST
under VERIFICATION TESTS.
NOTE:
Anti-lock Brake System (ABS) Controller Anti-Lock Brake (CAB) module may also be referred to as CAB controller.
- Turn ignition off. Connect scan tool to Data Link Connector (DLC). DLC is located on bottom of instrument panel, to left of brake pedal. See Figure . Turn ignition on. Using scan tool, attempt to communicate with ORC and EMIC. If scan tool communicates with both modules, go to next step. If scan tool does not communicate with both modules, proceed to COMPLETE PCI BUS FAILURE test.
- Turn ignition off. Disconnect 25-pin CAB module connector, located near left front strut tower. See Figure . Using ohmmeter, check resistance between ground and CAB module connector terminals No. 8 and 24, ground circuits. See Fig 1 . If resistance is less than one ohm in both circuits, go to next step. If resistance is one ohm or more on either circuit, repair open wires.
- Using voltmeter, check voltage between CAB module connector terminal No. 4, fused ignition switch output start/run circuit and ground. If voltage is 10 volts or more, go to next step. If voltage is less than 10 volts, repair open wire.
- Turn ignition off. Connect scan tool to Data Link Connector (DLC). DLC is located on bottom of instrument panel, to left of brake pedal. See Figure . Turn ignition on. Using scan tool, attempt to communicate with other modules. If scan tool does not communicate with other modules, proceed to COMPLETE PCI BUS FAILURE test. If scan tool communicates with other modules, go to next step.
- Connect Scope Input Cable (CH7058) to channel one connector on scan tool. Connect Red and Black leads, and Cable-To-Probe Adapter (CH7062) to scope input cable. Go to next step.
- Using scan tool, select DRB STANDALONE, LAB SCOPE, LIVE, then 12-VOLT SQUARE WAVE. Press F2 for scope. Press F2 again and use down arrow to set voltage range to 20 volts. Press F2 again. Go to next step.
- Connect black lead to ground. Connect Red lead to CAB harness connector terminal No. 10, PCI bus circuit. Turn ignition on. Observe voltage display on scan tool lab scope. If voltage pulses from zero to about 7.5 volts, replace CAB. See appropriate ANTI-LOCK article in BRAKES. If voltage remains at zero volts, repair open wire.