P1153

Circuit Description

The PCM provides a 0.45 volt reference signal to the oxygen sensor on CKT 412. When the oxygen sensor is cold, below 200°C (392°F), the oxygen sensor signal voltage will be around 0.45 volt and the PCM will keep the system in Open Loop operation. When the oxygen sensor is warm, above 200°C (392°F), the oxygen sensor will swing from rich to lean rapidly, if the PCM is in good control of the air fuel mixture. DTC P1153 is designed so that if the oxygen sensor is slow to respond to changes in exhaust oxygen content, then DTC P1153 will set.

Conditions for Running the DTC

^ DTCs P0117, P0118, P0121, P0122, P0123, and P0155 not set.
^ This test has not been completed yet this ignition cycle.
^ Low coolant level not present.

Conditions for Setting the DTC

^ Number of rich to lean transitions less than 20 in 120 seconds.
OR
^ Number of lean to rich transitions less than 20 in 120 seconds.

Action Taken When the DTC Sets

^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Notice: Do not solder heated oxygen sensor wires. Soldering the wires will result in the loss of the air reference to the sensor. If fault is not present perform Powertrain Ground Check and also review Failure Rec. to determine conditions under which and how long ago the DTC set. Component Tests and General Diagnostics

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. Checking if other possible causes of this DTC have already been diagnosed.
3. Diagnose other DTCs first because they may be the cause of this DTC setting.
4. With the engine running warm, coolant at least 85°C (185°F) and at fast idle, the oxygen sensor voltage should rapidly swing above 0.60 volt and below 0.30 volt.
6. Checking if the oxygen sensor voltage is swinging between rich and lean very slowly, or not at all.
8. Checking for causes of oxygen sensor failure. If sensor is replaced without finding cause of contamination, contamination of new sensor may result.