Test VPWR - Vehicle Power

NOTE: Enter this test only when directed here from CIRCUIT TESTS. To prevent replacement of good components, check for faults in the following non-EEC components: ignition switch, alternator, battery cables, ground straps or voltage regulator. This test is intended to diagnose only the following circuits: VPWR and GND.

Fig 1: Identifying VPWR Circuit & Connector Terminals

CIRCUIT PIN IDENTIFICATION

Circuit	Breakout Box Pin	ECA Pin
1.8L
VPWR	37, 57	1B
GND	39, 40, 44, 60	2A
GND	20	2B
GND	16	2C
2.2L (Non-Turbo MTX)
VPWR	37, 57	1B
GND	39, 40, 44, 60	2A
GND	20	2B
GND	16	2C
2.2L (All Others)
VPWR	37, 57	1B
GND	39, 40, 44, 60	3A
GND	20	3B
GND	16	3C

1) Checking Circuit Integrity Visually check all wiring, connectors and components for evidence of damage, shorting or looseness. If fault is found, repair as necessary. If no fault is found, check battery voltage and charge condition. Service as necessary and go to step 2).

2) Ground Circuit Check Turn ignition off and install breakout box. Turn ignition on. Measure voltage between the followings points.

VPWR test pin and battery ground
VPWR test pin and each ground test pin
VPWR test pin and each ECA ground wire

If all voltages are greater than 10 volts, go to CIRCUIT TEST VREF. If all voltages are less than 10 volts, repair as necessary.

3) VPWR From Main Relay Turn ignition off. Locate main power relay inside rectangular cover behind master cylinder reservoir. Disconnect main power relay 4-wire connector. Using jumper wire, attach BATT, PWR, and GND terminals to matching terminals in connector. Leave VPWR circuit disconnected.

4) Turn ignition on. Measure voltage between main power relay connector VPWR terminal and ground. If voltage is more than 10 volts, repair VPWR circuit between main power relay and ECA. If voltage is less than 10 volts, measure voltage between main power relay connector BATT terminal and ground.

5) If voltage is less than 10 volts, repair BATT circuit between main power relay and battery. If voltage is more than 10 volts, measure voltage between main power relay connector PWR terminal and ground. If voltage is less than 10 volts, repair PWR circuit between main power relay and ignition switch.

6) If voltage is more than 10 volts, measure voltage between main power relay connector BATT terminal and GND terminal. If voltage is less than 10 volts, repair main power relay ground wire. If voltage is not less than 10 volts, ground circuit is okay. Replace main power relay.