Idle Validation Switch (IVS)

1996 PCED OBDI

SECTION 18: Diesel Diagnosis — 7.3L DI Engine

AA: Idle Validation Switch (IVS)

AA1 DIAGNOSTIC TROUBLE CODE (DTC) 0221, 0220

Note: When performing KOER switch test, wait five seconds after pressing the trigger to start the test before running through the driver-operated controls. The test may also take up to five minutes to complete.

Key on/engine off.
NGS Tester installed.
Access AP and IVS PID.
Foot off accelerator pedal.

Does the IVS PID read "ON?"

Yes	No
GO to AA10.	GO to AA2.

AA2 IVS TRANSITION VOLTAGE CHECK

Depress accelerator pedal slowly while observing IVS state and AP voltage.

Does the IVS switch "ON" between .40v and 1.6v?

Yes	No
CLEAR DTCs and RETEST. If code is still present, REPLACE PCM.	GO to AA3.

AA3 IVS CHECK

Fully depress accelerator pedal while observing IVS.

Does IVS PID go "ON" at any pedal travel?

Yes	No
REPLACE accelerator pedal. CLEAR DTCs and RETEST.	GO to AA4.

AA4 IVS RESISTANCE CHECK

Disconnect IVS connector. Inspect for damaged or pushed out pins, corrosion, loose wires. Repair as necessary.
Measure resistance across IVS on accelerator pedal with accelerator pedal depressed.

Is resistance less than 5 ohms?

Yes	No
F-Series, GO to AA5. Econoline, GO to AA8.	REPLACE accelerator pedal assembly. CLEAR DTCs and RETEST.

AA5 IVS FUSE CHECK

Key on/engine off.
Check fuse 3 (3 amp) in IP fuse panel.

Is fuse 3 OK?

Yes	No
GO to AA6.	REPLACE fuse. CLEAR DTCs and RETEST.

AA6 CIRCUIT 16 (R/LG) RESISTANCE CHECK

Key on/engine off.
Remove Maxi fuse P (50 amp) from the power distribution box.
Measure resistance from the non-power side of fuse P to the power side of fuse 3.

Is resistance less than 5 ohms?

Yes	No
GO to AA7.	REPAIR open in Circuit 16 (R/LG) between power distribution box and IP fuse panel. REFER to EVTM for circuit information.

AA7 CIRCUIT 276 (BR) RESISTANCE CHECK

Key off.
Fuse 3 removed.
Measure resistance from non-power side of fuse 3 to Circuit 276 (BR) at IVS connector.

Is resistance less than 5 ohms?

Yes	No
GO to AA9.	REPAIR open in Circuit 276 (BR). REFER to EVTM for circuit information. CLEAR DTCs and RETEST.

AA8 CIRCUIT 16 (R/LG) RESISTANCE CHECK

Key off.
IVS connector disconnected.
Remove fuse U (30 amp) from power distribution box.
Measure resistance from the non-power side of fuse U to Circuit 16 (R/LG) at IVS connector.

Is resistance less than 5 ohms?

Yes	No
GO to AA9.	REPAIR open in Circuit 16 (R/LG) between power distribution box and IVS. REFER to EVTM for circuit information.

AA9 CHECK CIRCUIT 308 (R/O) FOR OPEN

Disconnect PCM. Inspect for damaged, pushed-out pins, corrosion, loose wires, etc. Service as necessary.
Connect breakout box, PCM disconnected.
Key off.
Check resistance between Circuit 308 (R/O) at IVS connector and Pin 5 on breakout box.

Is resistance less than 5 ohms?

Yes	No
REPLACE PCM. CLEAR DTCs and RETEST.	REPAIR open in Circuit 308 (R/O). CLEAR DTCs and RETEST.

AA10 CHECK CIRCUIT 308 (R/O) SHORT TO POWER

Disconnect IVS connector.

Does IVS PID read "OFF?"

Yes	No
REPLACE accelerator pedal. CLEAR DTCs and RETEST.	REPAIR short to power in IVS Circuit 308 (R/O).