The electrical current source is supplied from the engine control relay (terminal
No.3) to the glow control unit (terminal No.6). Also, it is supplied from the glow control unit
(terminal No.7) to the body earth.
The request signal of operating the glow plug is input into the glow control unit
(terminal No. 1) from the engine-ECU (terminal No.120).
The voltage for the glow plug is applied from the battery to the glow control unit
The voltage is applied from the glow control unit (terminal No.1, 2, 3 and 4) to
each glow plug.
The diagnosis signal is output from the glow control unit (terminal No.9) to the
engine-ECU (terminal No.126).
The voltage applied to the glow control unit (terminal No.10) from the battery
is applied to each glow plug in the duty ratio according to the signal from the engine ECU.
While the engine is running
The electrical continuity duty to the glow plug is 17 – 83 %.
The information that the glow is abnormal is received from the glow control unit.
Failed glow plug
Failed glow control unit
Open/short circuit or harness damage in glow plug circuit or loose connector contact.
STEP 1. Connector check: A-151 glow control unit connector