P1149

DTC P1149: Range/Performance Problem in Primary HO2S (Sensor 1) Circuit

NOTE: If some of the DTCs listed below are stored at the same time as DTC P1149 or P1165, troubleshoot those DTCs first, then troubleshoot DTC P1149 or P1165.

P0137, P0138: Secondary HO2S (Sensor 2) P0141: Secondary HO2S (sensor 2) Heater
1. Do the ECM/PCM Reset Procedure.
2. Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Check the Temporary DTC with the scan tool.
4. Test-drive under following conditions.
55 mph (89 kph) steady speed
- A/T in D4 position (M/T in 5th gear)
- Until readiness code or Temporary DTC P1149 (P1165) comes on
Is Temporary DTC P1149 (P1165) indicated?
YES-Replace the Primary HO2S (Sensor 1).
NO-Intermittent failure, system is OK at this time.
Check for poor connections or loose wires at C102 (located under the under-hood fuse/relay box). Primary HO2S relay, the Primary HO2S (Sensor 1) and the ECM/PCM.