P0135

O2 Sensor Heater Circuit Bank 1 Upstream Sensor.

P0135 - O2 sensor heater circuit bank 1 upstream sensor fault.: Last occurrence - plausibility

Possible causes:
1. Connector C0604, C0644.
2. Harness Integrity.
3. Oxygen sensor.

1. Connector C0604, C0644.
CONNECTOR
Check for connector not correctly latched, backed out pins, damaged pins, corroded pins

2. Harness Integrity.
CIRCUIT_INTEGRITY
Check for open circuit, short circuit to ground, supply or other circuit, damaged or unlatched connector, intermediate connectors or headers

3. Oxygen sensor.
No detail available for this fault