Signal Too Low
ECM-1200 INTAKE AIR TEMPERATURE (IAT) SENSOR INLET
SIGNAL TOO LOW
Diagnostic Trouble Code (DTC) status ECM-1200, Intake Air Temperature (IAT) sensor. Signal too low
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 Low - Intermittent Fault
Checking wiring and components
Check the signal cable between control module connector terminal A4 (# A4) and manifold absolute pressure (MAP) sensor connector terminal 3 for a short-circuit to ground 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.
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.
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.