Diagnostic Aids

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

The following table will be used to measure the resistance of the ambient air temperature sensor and compare it with the actual ambient temperature. The driver information center (DIC) temperature display accuracy should be within 5 degrees of the actual temperature. The actual temperature should not be taken from a radio station, a sign displaying the temperature, etc. A temperature measuring tool such as a thermometer should be used. Some temperature measuring tools may be within 5 degrees of the actual temperature. Make sure to consult the manufacturer for the accuracy of the tool. This comparison can make the DIC temperature display seem off by 5 - 10 degrees of the actual temperature when it is not.

If the ambient air temperature sensor resistance is less than 328 ohms, the IPC displays 'SC' (short circuit) in the DIC and this corresponds to a temperature of 125°C (257°F). If the ambient air temperature sensor resistance is greater than 353.37K ohms, the IPC displays 'OC' (open circuit) in the DIC and this corresponds to a temperature less than - 40°C (- 40°F). The IPC displays ' - - ' in the DIC when the IPC receives an invalid signal or there is a loss of serial data communication.

Ambient Air Temperature Sensor Resistance

°C	°F	Minimum Resistance K Ohms	Maximum Resistance K Ohms
-40	-40	313.74	353.37
-30	-22	167.22	184.93
-20	-4	92.81	100.79
-10	14	53.37	57.12
0	32	31.73	33.54
10	50	19.6	20.20
20	68	12.34	12.63
25	77	9.9	10.1
30	86	7.96	8.14
40	104	5.24	5.4
50	122	3.53	3.66
60	140	2.43	2.53
70	158	1.71	1.79
80	176	1.22	1.28
90	194	.89	.94
100	212	.65	.70
105	221	.56	.60
110	230	.49	.52
120	248	.37	.40
125	257	.32	.35