Signal Too Low
Signal too low
Diagnostic trouble code (DTC) status ECM-1300 Intake Air Temperature (IAT) Sensor. Signal too low
Reading off diagnostic trouble code (DTC) status ECM-1300
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 the connector
No - Intermittent fault
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Intermittent fault
Signal too low. Intermittent fault
Checking wiring and connectors
Check control module and mass air flow (MAF) sensor connectors for contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Check signal cable between control module #A22 (#A22) and mass air flow (MAF) sensor terminal 2 for an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Check ground lead between control module connector #A60 (#B2) and mass air flow (MAF) sensor connector terminal 5 for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
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 the connector
- Ignition off
- Check the mass Air Flow (MAF) sensor connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.
Other information:
- To access or replace the mass air flow (MAF) sensor, see the relevant service procedure.
Continue - Checking the connector
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Checking the connector
- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Start the engine. Allow the engine to idle
- Read off the mass air flow (MAF) sensor signal.
Check that the signal is within its permitted range. Voltage at idling speed must be 1.5-1.8V.
If the signal is now OK, the fault was caused by poor contact in the connector.
Other information:
- To access and replace the mass air flow (MAF) sensor, see
- For mass air flow (MAF) sensor table values, see Mass air flow (MAF) sensor Specifications.
Is the signal OK?
Yes - Verification
No - Checking the wiring and component
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Checking the wiring and component
Check the signal from the mass air flow (MAF) sensor. For actual voltage levels, see Mass air flow (MAF) sensor Specifications.
Check the signal cable between control module terminal #A22 (#A22) and mass air flow (MAF) sensor terminal 2. Check for a short-circuit to ground. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for an open-circuit. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the ground lead between control module connector terminal #A60 (#B2) and mass air flow (MAF) sensor connector terminal 5. Check for an open-circuit. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access or 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 connectors, reinstall components.
- Start the engine and let it idle.
- Read off the mass air flow (MAF) sensor signal.
The mass air flow (MAF) sensor signal should be approximately 1.5-1.8V at idling speed.
Is the mass air flow (MAF) sensor 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 - FAULT-TRACING FAILED
No - Attempt New Test
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FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - Diagnostic trouble code (DTC) status ECM-1300 Intake Air Temperature (IAT) Sensor. Signal too low
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