FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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02 Sensor 2/1 Heater Circuit Open

(P0155) 02 SENSOR 2/1 HEATER CIRCUIT OPEN





When Monitored and Set Condition
^ When Monitored: Engine Running and Heater duty cycle greater than 0%.
^ Set Condition: 02 Heater Temperature does not reach 575°C (959°F) within 90 seconds during monitoring conditions. Two Trip Fault.

POSSIBLE CAUSES
- 02 HEATER ELEMENT
- FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
- 02 HEATER CONTROL CIRCUIT OPEN
- POWERTRAIN CONTROL MODULE



Diagnostic Test
1. CHECK FOR CURRENT DTC





Turn the ignition on. With the DRBIII, read PCM DTCs.
Is this DTC present?
Yes >> For complete diagnosis of this DTC, refer to (P0135) 02 SENSOR 1/1 HEATER CIRCUIT HIGH 02 Sensor 1/1 Heater Circuit High
No >> Go To 2

2. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.

Note: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.

Note: Check for any Technical Service Bulletins that may apply.

Were there any problems found?
Yes >> Repair as necessary. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.