System Check
- Check for battery voltage at terminal 2 (Green/White wire) of pre-heating timer with ignition on. If no voltage is present, check for 1 volt at terminal 3 (Brown) and terminal 9 (White). If not present, replace current sensor. If voltage is present, replace pre-heating timer.
- Check that voltage at terminal 2 (Green/White) is no longer present after engine starts. If voltage is still present, disconnect alternator warning relay and retest. If okay with relay disconnected, repair charging system. If not, replace pre-heating timer.
- Turn ignition off and stop engine. Turn ignition on again and check that current flow to terminal 8 (Green/Red) at timer is present according to temperature chart. See Fig 1.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- If no voltage is present, replace timer. If voltage is present for wrong time, disconnect temperature sensor. Voltage should be present for 150 seconds, or 7 seconds with sensor lead grounded. If voltage is present as described, replace water temperature sensor. If time is still incorrect, replace timer.
- If voltage was present for correct period of time, check for voltage at terminal 8 (Green/Red) with ignition at "START" position. If no voltage, replace timer. If voltage is present, turn ignition off.
- Turn ignition on again. Check for voltage at glow plugs a few seconds later. If no voltage, check for battery voltage at positive side of current sensor (above No. 3 cylinder). If present, replace sensor. If not, replace No. 1 glow plug relay.
- Voltage at glow plugs should drop from 12 to 6 volts after a few seconds of operation. If not, check for battery voltage at positive side of ballast resistor (below intake manifold). If present, replace resistor. If not, replace No. 2 glow plug relay.
- If all voltage measurements are correct, measure glow plug resistance. Resistance should be close to zero. If infinity, replace glow plug.