Signal Too High

ECM-2120 FRONT HEATED OXYGEN SENSOR (HO2S), CONTROL ELEMENT
SIGNAL TOO HIGH

DTC status ECM-2120, Front Heated Oxygen Sensor (HO2S), control Signal too high



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

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

Was the status of the relevant Diagnostic Trouble Code (DTC) displayed as permanent?
Yes - Skip to "Checking Wiring and Components"
No - Continue below.


Checking cables



Check signal cable (+) between control module # A42 and transmission connector # 4 for an intermittent short-circuit to supply voltage according to [1][2]Checking Wiring and Terminals. Intermittent Faults and an intermittent short-circuit to ground according to [1][2]Checking Wiring and Terminals. Intermittent Faults

Check signal cable (-) between control module # A41 and transmission connector # 3 for an intermittent short-circuit to supply voltage according to [1][2]Checking Wiring and Terminals. Intermittent Faults and 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 Wiring and Components



Check signal cable (+) between control module # A42 and Heated Oxygen Sensor (HO2S) connector terminal # 4 for a short-circuit to supply voltage according to

Check signal cable (-) between control module # A41 and Heated Oxygen Sensor (HO2S) connector terminal 3 for a short-circuit to supply voltage according to
and a short-circuit to ground according to

If wiring is OK, try another Heated Oxygen Sensor (HO2S).

Remedy as necessary.

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- 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
- Start the engine and let it idle.
- Read the lambda value for the rear Heated Oxygen Sensor (HO2S).

Note! It takes approximately 25 seconds before fuel trim starts.

Check that the value is within its permitted range. The value should be approximately 0.98-1.02.

Is the value correct?
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.