I/O Circuit Check

I/O Circuit Check can help diagnose intermittent opens on all input signals to the Automatic Ride Control (ARC) module. What follows is the procedure to be used to determine if any input is intermittent.

NOTE: The I/O Circuit Check cannot be started without erasing all stored diagnostic trouble codes. If any DTCs are stored, either record the faults or repair and retest the system before proceeding to the I/O circuit test.

Test for intermittent open circuits by performing the following steps:

1. Configure the vehicle as follows:
a. Turn ignition on with engine oft
b. Place vehicle in PARK
c. Any door open (including the tailgate or tailgate window)
d. Select 4x4 low (if equipped) and wait for 4x4 low lamp to turn on
e. Apply service brakes using a block of wood or similar method
f. Fully apply throttle using a block of wood or similar method

I/O Circuit Table:

2. Using New Generation Star (NGS) Tester 007-00500 or equivalent, select PID monitor on the NGS. Ensure that the PIDs are set according to the I/O Circuit Table (this completes all circuits to the control module, any change that occurs will show an open circuit).
3. Enter I/O Circuit Check. All inputs should indicate "NO CHANGE". If not, then exit test and restart I/O Circuit Check.
4. Wiggle selected wiring harness without upsetting the vehicle.
5. If any inputs indicate 'CHANGED" then an intermittent open exists near the location that the wiring harness was wiggled and needs to be repaired.