Pinpoint Test As: Output Circuit Check Low
- 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.