1997 PCED OBDII-Diesel | SECTION 5C: Pinpoint Tests |
AN: Output Circuit Check (OCC) Low
AN1 DIAGNOSTIC TROUBLE CODE (DTC) P1661
- DTC P1661 indicates that the output circuit check is low.
- Possible causes:
- low battery voltage
- circuit failure
- damaged powertrain control module (PCM)
- Perform charging system and battery tests.
Is charging system OK?
| Yes | No |
|---|
| GO to AN2. | REPAIR charging system as required. |
AN2 VREF CIRCUIT CHECK
- Disconnect PCM. Inspect for damaged or pushed-out pins, corrosion and loose wires. Service as necessary.
- Install breakout box. Leave PCM disconnected.
- Disconnect manifold absolute pressure (MAP) sensor connector.
- Measure resistance between Pin 90 and VREF Circuit 351 (BR/W) at the MAP sensor connector.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to AN3. | IDENTIFY VREF circuit fault. GO to Pinpoint Test B1. |
AN3 VPWR CIRCUIT CHECK
- PCM disconnected.
- Key on.
- Measure resistance between Pins 71 and 97 and positive battery post.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to AN4. | IDENTIFY VPWR circuit failure. GO to Pinpoint Test A1. |
AN4 PCM GROUND CIRCUIT CHECK
- PCM disconnected.
- Key off.
- Measure resistance between Pins 25, 51, 76, 77 and 103 and negative battery post.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| REPLACE PCM. RETEST system. | REPAIR ground circuit fault. GO to Pinpoint Test A10. |