Central Control Module (CCM)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

CKTs 1294, 1295, and the Variable Effort Steering (VES) solenoid actuator are used to conduct the pulse width modulation for the variable effort system. The CCM has the ability to detect a problem in the VES circuits.

DTC WILL SET WHEN

This DTC will set when the VES function (at low speeds) is "ON" and the VES feedback exceeds 260 ma, or when the VES function is "ON" (at high speeds) and VES feedback is less than 360 ma.

ACTION TAKEN

DTC 28 will set. If the fault is a short to B+ a DTC 27 will also set. If CKT 1294, CKT 1295, or the Power Steering (P/S) pump and Electronic Variable Orifice (EVO) actuator are shorted to B+, shorted to ground or goes open, the CCM will completely disable the variable effort output.

DTC WILL CLEAR WHEN

Turning ignition "OFF" then "ON" again will reset DTC 28.

DTC CHART TEST DESCRIPTION

Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks for a shorted P/S pump and EVO actuator, normal P/S pump and EVO actuator, or too much resistance in VES circuits, or P/S pump and EVO actuator.

2. This test indicated if the P/S pump and EVO actuator, or circuit is causing a high resistance condition.

DIAGNOSTIC AIDS

If the DTC is a history DTC, the problem may be intermittent. Try performing the test shown while "wiggling" wiring and connectors; this can often cause the fault to appear.

A Tech 1 can be used to monitor the CCM VES output.