P1148 - Closed Loop Control Malfunction

The Mass Air Flow (MAF) sensor, Camshaft Position (CMP) sensor, and the front Heated Oxygen Sensor (H02S-11) circuits are monitored by the Powertrain Control Module (PCM). The test fails when the closed loop control function does not operate even when the vehicle is driving in the specified condition.

Possible Causes:
- The HO2S-11 circuit is open
- The HO2S-11 circuit is shorted to PWR
- The HO2S-11 circuit is shorted to GROUND
- The front HO2S
- The front HO2S heater

Diagnostic Aids:
The O2S-11 PID voltage should rise above 0.70 Volts at least once with the engine running at 2,000 rpm. The 02S-11 PID voltage should decrease below 0.21 Volts at least once with the engine running at 2,000 rpm.