Signal Too Low

Signal too low

Diagnostic trouble code (DTC) status ECM-1200, intake air temperature (IAT) sensor. Signal too low

Reading off diagnostic trouble code (DTC) status ECM-1200
Note! When reading off the diagnostic trouble code (DTC) status, other stored diagnostic trouble codes (DTCs) and their status will be listed.

- Read off 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 - Checking wiring and components

No - Intermittent fault

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Intermittent fault





Signal too low. Intermittent fault

Checking wiring and connectors
Check signal cable between control module #A22 (#A22) and mass air flow (MAF) sensor terminal 3 for an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults. The Intake Air Temperature (IAT) sensor is integrated into the Mass Air Flow (MAF) sensor.

Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access the control module, see
- To access/replace the Mass Air Flow (MAF) sensor, see
- For information about signals, see Signal specification Signal Description / Specification.










Continue - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

Do you want to view the information again?

Yes - Attempt New Test

No - Fault Found

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Attempt New Test - Checking wiring and connectors

DONE - DONE

FAULT FOUND - DONE

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DONE - DONE

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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 Checking wiring and terminals. Permanent fault 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, see Connecting the breakout box Connecting the Breakout Box
- To access / replace the control module see
- To access / replace the mass air flow (MAF) sensor, see
- For information about signals, see Signal specification Signal Description / Specification.










Continue - Verification

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Verification




Verification

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 off Intake Air Temperature (IAT) sensor signal. The Intake Air Temperature (IAT) sensor is integrated into the Mass Air Flow (MAF) sensor.
Check that the signal is OK according to the table value: Intake air temperature (IAT) sensor inlet Intake Air Temperature (IAT) Sensor Inlet.





Is the signal OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

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Fault-tracing information




Information

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.

Do you want to exit fault-tracing?

YES: Troubleshooting is complete for this DTC
NO: Repeat Procedure.

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