Signal Too High

ECM-1200 INTAKE AIR TEMPERATURE (IAT) SENSOR INLET
SIGNAL TOO HIGH

Diagnostic Trouble Code (DTC) status ECM-1200, Intake Air Temperature (IAT) sensor. Signal too high
Reading Diagnostic Trouble Code (DTC) status ECM-1200




Note! When Reading the Diagnostic Trouble Code (DTC) status, other stored Diagnostic Trouble Codes (DTCs) and their status will 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 - Continue below.
No - Signal Too High - Intermittent Fault


Checking the connector



- Ignition off.
- Check the Mass Air Flow (MAF) sensor connector for contact resistance and oxidation.
The Intake Air Temperature (IAT) sensor is integrated in the Mass Air Flow (MAF) sensor.

Other information:
- To access/replace the mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing
- For information about signals, Pinout Values and Diagnostic Parameters

Is the signal OK?
Yes - Skip to "Verification"
No - Contiue below.


Checking the Intake Air Temperature (IAT) sensor signal



- Ignition on.
- Engine running.
- Read the Intake Air Temperature (IAT) sensor signal.

Check that the signal is OK according to the table value: INTAKE AIR TEMPERATURE (IAT) SENSOR INLET ZZZZZZ
If the signal is now OK, the fault was caused by poor contact in the connector.

Other information:
- To access/replace the mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing
- For information about signals, Pinout Values and Diagnostic Parameters

Is the signal OK?
Yes - Skip to "Verification"
No - Contiue below.


Checking wiring and components



Check the Intake Air Temperature (IAT) sensor voltage between terminals 3 and 4 on the Mass Air Flow (MAF) sensor. The Intake Air Temperature (IAT) sensor is integrated in the Mass Air Flow (MAF) sensor. For voltage values, INTAKE AIR TEMPERATURE (IAT) SENSOR INLET ZZZZZZ

Check the signal cable between control module connector terminal A4 (# A4) and Mass Air Flow (MAF) sensor connector terminal 3 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault Also check for a short-circuit to supply voltage according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: With the ignition on and the Mass Air Flow (MAF) sensor connector disconnected, the voltage between terminal 3 and the ground terminal should be approximately 5V.

Check the ground lead between control module connector terminal A61 (# B3) and Mass Air Flow (MAF) sensor connector terminal 4 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

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 mass air flow (MAF) sensor, Mass Air Flow (MAF) Sensor, 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 the connectors, reinstall components etc.
- Ignition on.
- Read Intake Air Temperature (IAT) sensor signal. The Intake Air Temperature (IAT) sensor is integrated into the Mass Air Flow (MAF) sensor.

Check that that signal is OK according to the table value. ZZZZZZ

Is the signal 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.