Code 16

INTAKE AIR TEMPERATURE SENSOR AND CIRCUIT - DTC 16

The ECM looks for the intake air temperature sensor signal voltage out of the normal operating range.

The intake air temperature sensor is a negative temperature coefficient sensor; the higher the temperature, the lower the resistance. The sensor is located in the air intake elbow.

Temperature Versus Resistance Chart:

Temperature Versus Voltage Chart:

The intake air temperature sensor signal is used by the ECM for a correction to the mapped ignition timing. Ignition retard is applied at higher intake air temperatures and higher load sites.

The ECM will flag DTC 16 if the signal voltage is less than 0.1 volt or greater than 4.9 volts any time the ignition is ON.

Conditions Required for DTC 16 Flagging

Intake air temp. sensor voltage signal to ECM: Less than 0.1 volt or greater than 4.9 volts
Conditions monitored: Any time during ignition ON
Response time:64 milliseconds

Limp Home Default
If DTC 16 is flagged, the ignition air temperature strategy defaults to a trim value of 3O°C (86°F).

NOTE: If the intake air temperature exceeds 3O°C (86°F) (during default), detonation or pinging may occur.

Possible Faults
- High resistance connection at the air temperature sensor or ECM
- High resistance or open circuit wiring from the ECM to the intake air temperature sensor
- Short circuit wiring from the ECM to the intake air temperature sensor
- Defective intake air temperature sensor

Diagnostic Notes
1. The air temperature signal voltage can be monitored and intermitter faults captured using the PDU "Data logger" function.






2. If DTC 11,12,14, 18,19 and/or 39 are also flagged. suspect a defective sensor ground circuit to the ECM (BY wire) or defective ECM ground circuit to the front bulkhead ground stud.

Circuit Diagram

Circuit Diagram:

Flow Chart: DTC 16

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Flow Chart: DTC 16: