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 DTC U0166 [MZR-CD (RF Turbo)]

DTC U0166 [MZR-CD (RF Turbo)]

id0102f1035000

DTC U0166

Communication error to water heater unit

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

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.
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.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
• Perform the "After Repair Procedure".
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.