Test B - Vehicle Battery
To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault: battery cables and ground straps, voltage regulator and alternator, and ignition switch.
- Turn key on, leaving engine off. Set DVOM on 20-volt scale and measure voltage across battery terminals. If reading is less than 10.5 volts, service or replace discharged battery. If reading is 10.5 volts or higher, go to next step.
- Turn key off, wait 10 seconds. With breakout box installed and ECA connected, set DVOM on 200-ohm scale and measure resistance between test pins No. 40 and 60 and negative battery post. If reading is less than 0.5 ohms, go to next step. If reading is 0.5 ohms or higher, correct cause of resistance between negative side and pins No. 40 or 60. Repeat QUICK TEST .
- With breakout box installed and ECA connected, turn key off and wait 10 seconds. Set DVOM on 200-ohm scale. Measure resistance between test pins No. 46, 40 and 60. If either reading is 0.5 ohms or less, go to step 4). If resistance is more than 0.5 ohms, disconnect ECA and inspect for corrosion or damage. Repair and recheck resistance. If reading is still too high, replace ECA and repeat QUICK TEST .
- With breakout box installed and ECA connected, turn key off and wait 10 seconds. Set DVOM on 200-ohm scale. Measure resistance between test pin 46 and test pins 40 and 60. If reading is 5 ohms or less, go to step 5). If reading is more than 5 ohms, correct cause of resistance in Signal Return harness. Repeat QUICK TEST .
- Turn key on leaving engine off. With ECA connected, set DVOM on 20-volt scale. Measure voltage between battery negative post and Keep Alive Power (KAPWR) circuit (test pin No. 1) at EEC power relay. If reading is less than 10.5 volts, check KAPWR and vehicle power (V Power) circuits for shorts to ground. Also check KAPWR circuit from EEC power relay to battery positive post for open circuit. If reading is 10.5 volts or higher, go to next step.
- Turn key on, leaving engine off. With ECA connected, set DVOM on 20-volt scale. Measure voltage between battery negative post and ignition circuit at EEC power relay. If reading is less than 10.5 volts, check for open ignition switch circuits. Repair wiring and repeat QUICK TEST . If reading is 10.5 volts or higher, go to next step.
- Turn key off, wait 10 seconds. With ECA connected, set DVOM on 200-ohm scale. Measure resistance between battery negative post and ground circuit at EEC power relay. If reading is 0.5 ohms or less, go to next step. If reading is higher, repair open circuit or short to ground in ground circuit and repeat QUICK TEST .
- Turn key on, leaving engine off. With ECA connected, set DVOM on 20-volt scale. Measure voltage between battery negative post and vehicle power circuit at EEC power relay. If reading is less than 10.5 volts, replace EEC power relay and repeat QUICK TEST . If reading is 10.5 volt or higher, repair open vehicle power circuit. If okay, repair short to ground in vehicle power relay circuit.
- Turn key on, leaving engine off. Connect VOM or STAR tester to SELF-TEST connector. With SELF-TEST deactivated, enter into CONTINUOUS MONITOR (WIGGLE) TEST . Observe VOM or STAR tester LED for indication of fault while bending and twisting harness from EEC power relay to ECA. If code 72 or 78 is displayed or if fault is indicated, isolate fault in vehicle power circuit, and repair as necessary. If code 72 or 78 is not displayed or if fault is not indicated, inspect EEC power relay and connectors for damaged pins, corrosion, etc. If okay, replace EEC power relay and repeat QUICK TEST .