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DTC U0166 [MZR-CD (RF Turbo)]

id0102f1035000

DTC U0166 | Communication error to water heater unit
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DETECTION CONDITION | • PCM cannot receive any signals from water heater unit. Diagnostic support note • FREEZE FRAME DATA is available. • DTCs are stored in the PCM memory.
POSSIBLE CAUSE | • Connector or terminal malfunction • Short to ground in wiring between Water heater unit terminal 2C and PCM terminal 95 • Short to ground in wiring between Water heater unit terminal 2E and PCM terminal 87 • Open circuit in wiring between Water heater unit terminal 2C and PCM terminal 95 • Open circuit in wiring between Water heater unit terminal 2E and PCM terminal 87 • Short to power supply in wiring between Water heater unit terminal 2C and PCM terminal 95 • Short to power supply in wiring between Water heater unit terminal 2E and PCM terminal 87 • Water heater unit malfunction • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
No | Record FREEZE FRAME DATA on the repair order, then go to the next step.
2 | VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Check for related Service Bulletins and/or on-line repair information availability. • Is any related repair information available? | Yes | Perform the repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | VERIFY RELATED PENDING CODE OR STORED DTCS • Turn engine switch off, then to the ON position (Engine off). • Verify related pending code or stored DTCs. • Is DTC U0073 for present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [MULTIPLEX COMMUNICATION SYSTEM].)
No | Go to the next step.
4 | INSPECT WATER HEATER UNIT CONNECTOR FOR POOR CONNECTION • Turn engine switch off. • Disconnect the water heater unit connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace the suspected terminal, then go to Step 9.
No | Go to the next step.
5 | INSPECT CAN COMMUNICATION LINE FOR SHORT TO GROUND • Inspect for continuity between the following terminals and body ground: - Water heater unit connector terminal 2C (wiring harness-side) - Water heater unit connector terminal 2E (wiring harness-side) • Is there continuity? | Yes | Repair or replace the suspected wiring harness, then go to Step 9.
No | Go to the next step.
6 | INSPECT CAN COMMUNICATION LINE FOR SHORT TO POWER SUPPLY • Measure the voltage between following terminals and body ground: - Water heater unit connector terminal 2C (wiring harness-side) - Water heater unit connector terminal 2E (wiring harness-side) • Is the voltage B+? | Yes | Repair or replace the suspected wiring harness, then go to Step 9.
No | Go to the next step.
7 | INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn engine switch off. • Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].) • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace the suspected terminal, then go to Step 9.
No | Go to the next step.
8 | INSPECT CAN COMMUNICATION LINE FOR OPEN CIRCUIT • Inspect for continuity between the following terminals: - Water heater unit connector terminal 2C (wiring harness-side) and PCM connector terminal 95 (wiring harness-side) - Water heater unit connector terminal 2E (wiring harness-side) and PCM connector terminal 87 (wiring harness-side) • Is there continuity? | Yes | Repair or replace the suspected wiring harness, then go to the next step.
No | Go to the next step.
9 | VERIFY TROUBLESHOOTING OF DTC U0166 COMPLETED • Make sure to reconnect all disconnected connectors. • Turn engine switch to the ON position (Engine off). • Clear the DTC from the PCM memory using the WDS or equivalent. • Start the engine and warm it up completely. • Is the same DTC present? | Yes | Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
No | Go to the next step.
10 | VERIFY AFTER REPAIR PROCEDURE • Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE [MZR-CD (RF Turbo)].) • Are any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [MZR-CD (RF Turbo)].)
No | Troubleshooting completed.