Power Circuits
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Using a DVOM, check for battery voltage between ground and B+ circuit at PCM terminal No. 55 (104-pin PCM), terminal No. B40 (122-pin PCM), terminal No. B45 (150-pin PCM - Focus 2.3L), or terminal No. A44 or B44 (150-pin PCM - all others). See Fig 1-Fig 4 . Turn ignition switch to START or RUN position. Check for battery voltage between ground and specified VPWR circuit at PCM harness connector. See PCM VPWR CIRCUIT TERMINAL IDENTIFICATION table. If battery voltage is not present, check for an open in VPWR circuit between PCM and PCM power relay. For additional testing procedures, see TEST B: EEC-V POWER RELAY under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.
PCM VPWR CIRCUIT TERMINAL IDENTIFICATION
| Application | (1) PCM Terminal No. | ||
|---|---|---|---|
| Models With 122-Pin PCM | B34 & B46 | ||
| Focus 2.3L With 150-Pin PCM | B35 & B36 | ||
| All Other Models With 150-Pin PCM | A32 & A33, Or B32 & B33 | ||
| All Other Models | 71 | ||
|
|||