Pinpoint Test As: Output Circuit Check Low

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1996 Ford RV Cutaway, 1996 Ford Pickup, 1996 Ford F-Super Duty, 1996 Ford Econoline, and 1996 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

1) DTC 1661

This DTC indicates that output circuit check is low. self-test range. Possible causes for this DTC are:
- Low battery voltage.
- VREF circuit fault.
- Faulty Powertrain Control Module (PCM).
Perform charging system and battery tests. See appropriate STARTING & CHARGING SYSTEMS article in ACCESSORIES & EQUIPMENT. Repair as necessary. If charging system is okay, go to next step.

2) Check VREF Circuit

Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Disconnect Manifold Absolute Pressure (MAP) sensor connector. Measure resistance between Brown/White wire at MAP sensor wiring harness connector and test pin No. 90 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair VREF circuit (Brown/White wire). Clear DTCs, and repeat QUICK TEST .

3) Check VREF Circuit

Turn ignition on. Measure resistance between test pins No. 71 and 97 at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair VREF circuit (Brown/White wire). Clear DTCs, and repeat QUICK TEST .

4) Check PCM

Turn ignition off. Measure resistance between ground and test pins No. 25, 51, 76, 77 and 103 at breakout box. If all readings are less than 5 ohms, replace PCM. Clear DTCs, and repeat QUICK TEST . If any reading is 5 ohms or more, fault exists in PWR GND circuit. Go to TEST A, step 10) to check PWR GND circuit.