LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2003 >> Crown Victoria Base, 4.6 9 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Tests - CNG >> Computerized Engine Controls >> Powertrain Control Module >> Power Circuits
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Circuits

  1. Turn ignition off. Using DVOM, check for battery voltage between chassis ground and PCM Keep Alive Memory Power (KAPWR) terminal No. 55. See Fig 1 or Fig 2 . If battery voltage is not present, check for open in KAPWR circuit or fuse battery junction box No. 12 (30-amp) on Crown Victoria, battery junction box fuse No. 4 (10-amp) on Econoline, or central junction box fuse No. 2 (5-amp) on F150 Pickup. See ENGINE PERFORMANCE in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If battery voltage is present, go to next step.
  2. Turn ignition on. Using DVOM, check for battery voltage between chassis ground and VPWR at PCM connector terminals No. 71 (all models) and No. 97 (except Crown Victoria). If battery voltage is not present, power is not being supplied from PCM power relay. See TEST B: EEC-V POWER RELAY under SYSTEM TESTS in SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article.
Fig 1: Identifying Powertrain Control Module Connector Terminals (Crown Victoria & Econoline)
G00011522Courtesy of FORD MOTOR CO.
Fig 2: Identifying Powertrain Control Module Connector Terminals (F150)
G96F31315Courtesy of FORD MOTOR CO.
scientia non olet · About LEMON Manuals