Signal Too Low

ECM-2200 REAR HEATED OXYGEN SENSOR (HO2S)
SIGNAL TOO HIGH

Diagnostic Trouble Code (DTC) status ECM-2200, Rear Heated Oxygen Sensor (HO2S), control. Signal too low



Note! When Reading the Diagnostic Trouble Code (DTC) status, other stored Diagnostic Trouble Codes (DTCs) and their status will also be listed.

Read the Diagnostic Trouble Code (DTC) status. Check the status of the relevant Diagnostic Trouble Code (DTC).

Was the status of the relevant Diagnostic Trouble Code (DTC) permanent?
Yes - Skip to "Checking the Connector"
No - Continue below.


Checking wiring



Caution!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Check the rear Heated Oxygen Sensor (HO2S) connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Check the signal cable between control module terminal A24 and Heated Oxygen Sensor (HO2S) connector terminal 4 for an intermittent open-circuit according to according to [1][2]Checking Wiring and Terminals. Intermittent Faults Check for an intermittent short-circuit to ground according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Check the signal cable (-) between control module terminal A61 and Heated Oxygen Sensor (HO2S) connector terminal 3 for an intermittent open-circuit according to [1][2]Checking Wiring and Terminals. Intermittent Faults Check for an intermittent short-circuit to ground according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
--Testing Complete--


Checking the connector



- Ignition off.

Check the rear Heated Oxygen Sensor (HO2S) connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Permanent Fault

Caution!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Remedy as necessary.

Other information
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Checking the connector



- Ignition off.
- Reinstall the components, reconnect the connectors etc.
- Start the engine and let it idle.
- Read the signal for the rear Heated Oxygen Sensor (HO2S).

Note! It takes approximately 50 seconds before fuel trim starts.

Check that the signal is within its permitted range. The signal should rise and exceed 0.67 V.

If the value is now OK, the cause of the fault was loose connections in the connector.

Other information
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters

Is the value OK?
Yes - Testing Complete.
No - Continue below.


Checking wiring and components




Caution!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Check the signal cable between control module terminal A24 and Heated Oxygen Sensor (HO2S) connector terminal 4 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault Check for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault


Check the signal cable between control module terminal A61 and Heated Oxygen Sensor (HO2S) connector terminal 3 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault Check for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Try a new Heated Oxygen Sensor (HO2S) if the wiring is OK.

Remedy as necessary.

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect connectors, reinstall components etc.
- Start the engine and let it idle.
- Read the signal from the rear Heated Oxygen Sensor (HO2S).

Note! It takes approximately 50 seconds before fuel trim starts.

Check that the signal is within its permitted range. The signal should rise and exceed 0.67 V.

Is the value OK?
Yes - Testing Complete
No - Continue Below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.