Pinpoint Test QA: Unable To Activate Self-Test/Network Communication Error: Introduction
NOTE:
PCM diagnostic tool protocol is dependant upon vehicle application and configuration. Refer to the appropriate SYSTEM WIRING DIAGRAMS
for schematic and connector information. Refer to the appropriate MODULE COMMUNICATIONS NETWORK
article
for description and operation information.
This pinpoint test addresses the following concerns:
- unable to communicate with PCM
- unable to activate the PCM self-test.
Possible causes:
- incorrect self-test procedure
- communication circuit open from PCM to the DLC
- PCM voltage or ground circuits PCM
- VREF circuit short to ground (Ford GT or Ranger)
PCM COMMUNICATION PROTOCOL AND VREF INFORMATION CHART
| Application | Engine | PCM Protocol | Measure the PCM VREF at: |
|---|---|---|---|
| E-150/E-250 | 4.6L | CAN | FRP |
| Escape/Mariner | All | CAN | TPS or FRPT |
| F-150 | 4.6L | CAN | FRP |
| Focus | All | CAN | TPS or FRPT |
| Ford GT | All | SCP | TPS |
| Freestar/Monterey | All | CAN | TPS |
| Fusion/Milan/Zephyr | All | CAN | ETBTPS |
| Lincoln LS | All | CAN | FRP |
| Ranger | All | SCP | TPS |
| Taurus | All | CAN | TPS |
| All Others | All | CAN | FRPT |
POWERTRAIN CONTROL MODULE (PCM) CONNECTOR CHART
| Vehicle | Connector | Pin | Circuit |
|---|---|---|---|
| E-Series 4.6L, E-Series 5.4L, Mustang | 170 | Pin B47, B48, B49, B50 | PWRGND |
| B35, B36 | VPWR | ||
| E-Series 6.8L, F-Super Duty | 170 Pin | B47, B48, B49, B50 | PWRGND |
| B35, B36, T39 | VPWR | ||
| Escape, Focus, Mariner | 150 (50-50-50) Pin | B47, B48, B49 | PWRGND |
| B35, B36 | VPWR | ||
| Expedition, Navigator | 190 Pin | B67, B68, B69, B70 | PWRGND |
| B51, B52, B53 | VPWR | ||
| Explorer, Mountaineer | 170 Pin | B47, B48, B49, B50 | PWRGND |
| B35, B36 | VPWR | ||
| B37 | PCMRC | ||
| B46 | ISP-R | ||
| F-150, Mark LT | 190 Pin | B67, B68, B69, B70 | PWRGND |
| B51, B52, B53 | VPWR | ||
| B40 | PCMRC | ||
| B17 | ISP-R | ||
| Freestar/Monterey | 104 Pin | 103, 24, 51, 76 | PWRGND |
| 71, 97 | VPWR | ||
| Fusion, Milan, Zephyr | 140 Pin | B67, B68, B69 | PWRGND |
| B51, B52 | VPWR | ||
| B35 | PCMRC | ||
| B37 | ISP-R | ||
| Ford GT | 104 Pin | 103, 3, 51, 76 | PWRGND |
| 71, 97 | VPWR | ||
| LS | 150 (60-32-58) Pin | B24, B25, B26, B27 | PWRGND |
| B32, B33 | VPWR | ||
| Ranger, Taurus | 104 Pin | 103, 24, 51, 76, 77 | PWRGND |
| 71, 97 | VPWR | ||
| All other vehicles | 150 (50-50-50) Pin | B47, B48, B49, B50 | PWRGND |
| B35, B36 | VPWR |