Mazda Mazda6 - Page 890

U–24
ON-BOARD DIAGNOSTIC
DTC B2449, B2450
A6E857001038206
Diagnostic procedure
End Of Sie
DTC B2451, B2452
A6E857001038207
Diagnostic procedure
DTC
B2449 Glow plug circuit short to ground
B2450 Glow plug circuit open
DETECTION
CONDITION
• CPU detects malfunction in glow plug circuit
POSSIBLE
CAUSE
• Water heater unit malfunction
STEP INSPECTION ACTION
1 INSPECT WATER HEATER UNIT
• Replace the water heater unit. (See U–15
WATER HEATER UNIT REMOVAL/
INSTALLATION)
• Perform the combustion Test. (See U–22 KOEO
Self Test/Combustion Test.)
• Are any DTCs present?
Yes Go to the applicable DTC troubleshooting.
No Troubleshooting completed.
DTC
B2451 Fuel pump (water heater system) circuit short to ground
B2452 Fuel pump (water heater system) circuit open
DETECTION
CONDITION
• CPU detects malfunction in fuel pump (water heater system) circuit
POSSIBLE
CAUSE
• Fuel pump (water heater system) malfunction
• Water heater unit malfunction
• Short to ground between water heater unit terminal B and fuel pump (water heater system) terminal A
• Open circuit between water heater unit terminal B and fuel pump (water heater system) terminal A
• Open circuit between fuel pump (water heater system) terminal B and GND
ACE
BDF
WATER HEATER UNIT CONNECTOR
FUEL PUMP
(WATER HEATER SYSTEM)
CONNECTOR
A
B
STEP INSPECTION ACTION
1 INSPECT WIRING HARNESS BETWEEN
WATER HEATER UNIT AND FUEL PUMP
(WATER HEATER SYSTEM) FOR
CONTINUITY
• Start the engine.
• Is the voltage at fuel pump (water heater
system) connector terminal A approximately
12 V?
Yes Go to the next step
No Repair the wiring harness.
2 INSPECT FUEL PUMP (WATER HEATER
SYSTEM)
• Inspect the fuel pump (water heater system).
(See U–16 FUEL PUMP (WATER HEATER
SYSTEM) INSPECTION)
• Is the fuel pump (water heater system) okay?
Yes Go to the next step
No Replace the fuel pump (water heater system).
(See U–15 WATER HEATER UNIT REMOVAL/
INSTALLATION)
3 INSPECT WIRING HARNESS BETWEEN
FUEL PUMP (WATER HEATER SYSTEM) AND
GROUND FOR CONTINUITY
• Is there continuity between the fuel pump
(water heater system) connector terminal B
and ground?
Yes Go to the next step
No Repair the wiring harness.