P0674: Glow Plug (Circuit Low) (#4Cyl), Glow Plug (Circuit High) - Hino Motors HINO 155 series Workshop Manual

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P0674: Glow plug (Circuit low) (#4cyl), Glow plug (Circuit high) (#4cyl)
INFORMATION
ECU
1. Technical description
• Glow plug is controlled by GCU.
• The indicator in the meter lights up when a failure (malfunction caused by short-circuit or disconnection) occurs in
the glow system.
<Description of malfunction>
• Circuit failure between the GCU and glow plug #4 is detected.
2. DTC set condition
(1) DTC detection condition
• Starter key is "ON".
• The engine ECU instructs glow discharge.
The conditions described below remain for 1 second or more.
- The battery voltage is in the range of 10 to 16 V.
- Starter is not actuated.
(2) Judgement criteria
• The condition that the glow plug operating current is less than the range of 0.5 to 0.9 A remains for 0.3 sec-
onds or more, or the condition that the glow plug operating current is greater than the range of 21 to 36 A
remains for 0.3 seconds or more.
3. Reset condition
• Immediately after normal operation is restored.
4. Indication, warning or system control regulation when the DTC is set.
• MIL: ON
• SVS light: OFF
5. Symptoms on the vehicle when the DTC is set
<Symptoms on the vehicle due to backup control (fail safe function)>
• –
<Symptoms on the vehicle due to malfunction>
• Vehicle is difficult to start.
ENGINE (J05E)/TROUBLESHOOTING
ENG3
GCU
BATT
+B
ST SI
Control signal
+B
DI DI
Diagnosis signal
+B
Glow
+B
GL1 GLW1 Glow Plug 1
GL2 GLW2 Glow Plug 2
GL3 GLW3 Glow Plug 3
GL4 GLW4 Glow Plug 4
#1cyl
#2cyl
#3cyl
#4cyl
SHTS021270300633