Pinpoint Test AD: The Outside Air Temperature Display Does Not Operate Correctly
Instrumentation, Message Center and Warning Chimes
Pinpoint Test AD: The Outside Air Temperature Display Does Not Operate Correctly
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information Electrical Diagrams.
Normal Operation
The Ambient Air Temperature (AAT) sensor is hardwired to the Instrument Panel Cluster (IPC) through the input and return circuits. The IPC (Instrument Panel Cluster) provides a reference voltage to the AAT (Ambient Air Temperature) sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature. The IPC (Instrument Panel Cluster) is programmed to update the displayed temperature at different rates depending on several criteria to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the AAT (Ambient Air Temperature) sensor than the actual outside air temperature.
The IPC (Instrument Panel Cluster) uses the last displayed temperature reading, engine coolant temperature and length of time the engine is off to determine how the display is updated. The IPC (Instrument Panel Cluster) stores the last temperature reading at key off and then compares the value against the current temperature reading. When the current temperature reading is below the stored temperature reading, the engine has been off for 2.5 hours or the engine coolant temperature is below 45°C (32°F), the IPC (Instrument Panel Cluster) displays the current outside air temperature as measured by the AAT (Ambient Air Temperature) sensor.
If the IPC (Instrument Panel Cluster) fails any of the above criteria, the display is updated according to the following table:
Early Build Update Rate
Late Build Update Rate
- DTC B1A68:11 (Ambient Temperature Sensor: Circuit Short To Ground)- a continuous and on-demand DTC that sets if the IPC (Instrument Panel Cluster) detects a short to ground on the AAT (Ambient Air Temperature) sensor input circuit. If the IPC (Instrument Panel Cluster) detects a short to ground on the outside air temperature input, the IPC (Instrument Panel Cluster) defaults the display to dashes (----).
- DTC B1A68:13 (Ambient Temperature Sensor: Circuit Open)- a continuous and on-demand DTC that sets if the IPC (Instrument Panel Cluster) detects an open on the AAT (Ambient Air Temperature) sensor input circuit. If the IPC (Instrument Panel Cluster) detects an open on the outside air temperature input, the IPC (Instrument Panel Cluster) defaults the display to dashes (----).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- AAT (Ambient Air Temperature) sensor
- IPC (Instrument Panel Cluster)
PINPOINT TEST AD : THE OUTSIDE AIR TEMPERATURE DISPLAY DOES NOT OPERATE CORRECTLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
AD1 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST
- Check for recorded IPC (Instrument Panel Cluster) DTCs from the self-test.
Is IPC (Instrument Panel Cluster) DTC B1A68:11 or DTC B1A68:13 recorded?
Yes
GO to AD4.
No
VERIFY the vehicle has been driven to eliminate any potential heat soak condition and cool off the sensor.
If the outside air temperature display is still inaccurate, GO to AD2.
AD2 VERIFY THE SPEEDOMETER OPERATION
- Operate the vehicle and verify the speedometer operation.
Does the speedometer operate correctly?
Yes
GO to AD3.
No
GO to Pinpoint Test E Pinpoint Test E: The Speedometer Is Inoperative.
AD3 CHECK THE AMBIENT AIR TEMPERATURE SENSOR FUNCTION
- Ignition OFF.
- Disconnect: Ambient Air Temperature Sensor C132.
- Measure the resistance between the ambient air temperature sensor C132 pin 2, component side and the ambient air temperature sensor C132 pin 1, component side according to the following table.
Ambient Air Temperature Ambient Air Temperature Sensor Resistance 0-10°C (32-50°F) 5179-3838 ohms 10-20°C (50-68°F) 3838-2792 ohms 20-30°C (68-86°F) 2792-1978 ohms 30-40°C (86-104°F) 1978-1392 ohms
Does the ambient air temperature sensor resistance match the ambient air temperature according to the table?
Yes
The system is operating normally at this time. EXPLAIN to the customer the normal operation of the system.
No
CHECK the connector for corrosion or pushed out pins. If the connector is OK, INSTALL a new ambient air temperature sensor. TEST the system for normal operation.
AD4 CLEAR THE DTCs AND RECHECK THE SYSTEM
- Clear the DTCs and repeat the IPC (Instrument Panel Cluster) self-test.
Is IPC (Instrument Panel Cluster) DTC B1A68:11 or DTC B1A68:13 recorded?
Yes
GO to AD5.
No
The system is operating normally at this time.
AD5 CHECK THE AMBIENT AIR TEMPERATURE SENSOR FUNCTION
- Ignition OFF.
- Disconnect: Ambient Air Temperature Sensor C132.
- Ignition ON.
- Measure the voltage between the ambient air temperature sensor C132-1, circuit VH407 (YE/GN), harness side and the ambient air temperature sensor C132-2, circuit RH107 (GN/BU), harness side.
Is the voltage approximately 5 volts?
Yes
INSTALL a new ambient air temperature sensor. CLEAR the DTCs. REPEAT the self-test.
No
GO to AD6.
AD6 CHECK THE OUTSIDE AIR TEMPERATURE SENSOR INPUT AND RETURN CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: IPC (Instrument Panel Cluster) C220.
- Ignition ON.
- Measure the voltage between the IPC (Instrument Panel Cluster) C220-20, circuit VH407 (YE/GN), harness side and ground; and between the IPC (Instrument Panel Cluster) C220-19, circuit RH107 (GN/BU), harness side and ground.
Is any voltage present?
Yes
REPAIR the circuit in question for a short to voltage. REPEAT the self-test. CLEAR the DTCs.
No
GO to AD7.
AD7 CHECK THE OUTSIDE AIR TEMPERATURE INPUT CIRCUIT FOR AN OPEN AND SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between the IPC (Instrument Panel Cluster) C220-20, circuit VH407 (YE/GN), harness side and the ambient air temperature sensor C132-1, circuit VH407 (YE/GN), harness side; and between the IPC (Instrument Panel Cluster) C220-20, circuit VH407 (YE/GN), harness side and ground.
Is the resistance less than 5 ohms between the IPC (Instrument Panel Cluster) and the ambient air temperature sensor, and greater than 10,000 ohms between the IPC (Instrument Panel Cluster) and ground?
Yes
GO to AD8.
No
REPAIR circuit VH407 (YE/GN) for an open or for a short to ground. TEST the system for normal operation.
AD8 CHECK THE OUTSIDE AIR TEMPERATURE RETURN CIRCUIT FOR AN OPEN
- Measure the resistance between the IPC (Instrument Panel Cluster) C220-19, circuit RH107 (GN/BU), harness side and the ambient air temperature sensor C132-2, circuit RH107 (GN/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to AD9.
No
REPAIR circuit RH107 (GN/BU) for an open. CLEAR the DTCs. REPEAT the self-test.
AD9 CHECK FOR CORRECT IPC (Instrument Panel Cluster) OPERATION
- Disconnect all the IPC (Instrument Panel Cluster) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the IPC (Instrument Panel Cluster) connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.