Signal Too High - Permanent Fault

ECM-2A1A REAR HEATED OXYGEN SENSOR (HO2S) AGING
SIGNAL TOO HIGH - PERMANENT FAULT

Checking for air leakage in the exhaust system



Check for air leakage according to Checking For Air Leakage In the Exhaust System

Was there any air leakage?
Yes - Testing Complete.
No - Contine below.


Replacing component



Try a new Heated Oxygen Sensor (HO2S) according to Adapter Wiring Switch, Replacing

Other information
- Connecting the breakout box/accessing the control module Connecting the Breakout Box (ECM)
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


Verification



Hint: After carrying out the repair, check that the fault has been remedied.

- Ignition off.
- Reconnect connectors, reinstall components.
- Test drive car as follows:

A/C on Drive the car so that idle, normal and high speeds are reached. Let the car operate in these phases for a few minutes. Accelerate at full throttle a number of times so that high boost pressure is reached (applies only to turbo models). Total test drive time must be 15 minutes.

NOTE: After test driving the engine should not be turned off. The test drive must be carried out again.

Connect VIDA again and read out the Heated Oxygen Sensor (HO2S) Diagnostic Trouble Code (DTC) status.
The text NOT READY is displayed if diagnosis is underway.

Is FAULT NOT REGISTERED displayed?
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.