DTC B1D28:4B, B1D31:94, B1D32:92 [WATER HEATER SYSTEM]SM2445580
DTC B1D28:4B, B1D31:94, B1D32:92 [WATER HEATER SYSTEM]

id070228733600

DTC

B1D28:4B

Fuel pre-heater over temperature

B1D31:94

Flame detected prior to normal operation

B1D32:92

Multiple flame interruption during heating cycle
DETECTION CONDITION
• CPU detects malfunction in the water heater unit
POSSIBLE CAUSE
• Disturbance in the fuel supply
• Blocked air intake or exhaust of the water heater unit
• Water heater unit malfunction
― CPU malfunction
― Glow plug malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION
1
INSPECT FUEL SUPPLY SYSTEM
• Are there any problems on the fuel lines, or on the fuel supply system? (E.g. blocked fuel line)
Yes
Replace the fuel supply system, then go to Step 4.
No
Go to the next step.
2
INSPECT AIR INTAKE AND EXHAUST SYSTEM
• Are there any problems on the air intake or on the exhaust system? (E.g. blocked air intake, blocked exhaust pipe)
Yes
Replace the air intake or exhaust system, then go to Step 4.
No
Go to the next step.
3
INSPECT WATER HEATER UNIT
• Perform the water heater system operation check.
• Clear DTCs using the M-MDS.
• Perform the water heater unit DTC inspection using the M-MDS. (See DTC DISPLAY [WATER HEATER SYSTEM].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)
• Are DTCs B1D28:4B, B1D31:94 or B1D32:92 displayed?
Yes
Replace the water heater unit, then go to the next step.
(See WATER HEATER UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
No
Go to the next step.
4
VERIFY AFTER REPAIR PROCEDURE
• Perform after repair procedure. (See DTC DISPLAY [WATER HEATER SYSTEM].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)
• Are any DTCs present?
Yes
Go to the applicable DTC troubleshooting.
No
Troubleshooting completed.