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DTC B2451, B2452

id070200731200

DTC | B2451 | Fuel pump (water heater system) circuit short to ground
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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

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | INSPECT WIRING HARNESS BETWEEN WATER HEATER UNIT AND FUEL PUMP (WATER HEATER SYSTEM) FOR CONTINUITY • Start engine. • Is voltage at fuel pump (water heater system) connector terminal A approx. 12 V? | Yes | Go to next step
No | Repair wiring harness.
2 | INSPECT FUEL PUMP (WATER HEATER SYSTEM) • Inspect fuel pump (water heater system). (See FUEL PUMP (WATER HEATER SYSTEM) INSPECTION [MZR-CD (RF Turbo)].) • Is fuel pump (water heater system) okay? | Yes | Go to next step
No | Replace fuel pump (water heater system). (See WATER HEATER UNIT REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
3 | INSPECT WIRING HARNESS BETWEEN FUEL PUMP (WATER HEATER SYSTEM) AND GROUND FOR CONTINUITY • Is there continuity fuel pump (water heater system) connector terminal B and ground? | Yes | Go to next step
No | Repair wiring harness.
4 | INSPECT WATER HEATER UNIT • Clear the DTC. • Perform the KOEO Self Test. (SeeKOEO Self Test/Combustion Test.) • Is the same DTC present? | Yes | Replace the water heater unit. (See WATER HEATER UNIT REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
No | Go to the next step.
5 | VERIFY AFTER REPAIR PROCEDURE • Perform after repair procedure. (SeeAfter Repair Procedure.) • Are any DTCs present? | Yes | Go to the applicable DTC troubleshooting.
No | Troubleshooting completed.