DTC P1490: Low Speed Fan Control Relay Circuit

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

NOTE: Low speed fan control relay is referred to as low speed radiator fan relay in this test. Low speed radiator fan relay operation is monitored when ignition is on and battery voltage is more than 10 volts. DTC may be stored in Powertrain Control Module (PCM) if an open or shorted condition is detected in low speed radiator fan relay control circuit. Possible causes are; defective low speed radiator fan relay, defective PCM, or defective connectors or wiring.

Turn ignition on with engine off. Using scan tool, actuate low speed radiator fan relay. Listen for clicking sound at low speed radiator fan relay. Low speed radiator fan relay is located in power distribution center at driver's side front corner of engine compartment, near air cleaner assembly. See Figure . If clicking sound is heard at low speed radiator fan relay, go to next step. If no clicking sound is heard at low speed radiator fan relay, go to step 4 .
Turn ignition off. Inspect wiring harness and connectors between low speed radiator fan relay and PCM. PCM is located at driver's side front corner of engine compartment, just below air cleaner assembly. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary. Perform TEST VER-2A .
Turn ignition on with engine off. Using scan tool, actuate low speed radiator fan relay. Wiggle wiring harness and connectors between low speed radiator fan relay and PCM while low speed radiator fan relay is still actuated. If clicking sound at low speed radiator fan relay was not interrupted while wiggling wiring harness and connectors, test is complete. If clicking sound at low speed radiator fan relay was interrupted while wiggling wiring harness and connectors, repair wiring or connectors as necessary. Perform TEST VER-2A .
Turn ignition off. Remove low speed radiator fan relay from power distribution center. Note which terminals on low speed radiator fan relay correspond with cavities in power distribution center. See Figure . Using ohmmeter, check resistance between terminals on low speed radiator fan relay that corresponds with cavities No. 84 and 86 in power distribution center. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace low speed radiator fan relay. Perform TEST VER-2A .
Turn ignition on with engine off. Note identification of cavities in power distribution center for low speed radiator fan relay. See Figure . Using voltmeter, check voltage at cavity No. 84 (Light Green/Black wire) in power distribution center for low speed radiator fan relay. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open on Light Green/Black wire to low speed radiator fan relay. The Light Green/Black wire goes from cavity No. 84 in power distribution center for low speed radiator fan relay to fuse No. 9 (10-amp). Fuse No. 9 is located in power distribution center and receives voltage from ignition switch. Perform TEST VER-2A .
Ensure ignition is off. Disconnect PCM connectors. PCM is located at driver's side front corner of engine compartment, just below air cleaner assembly.
Note identification of cavities in power distribution center for low speed radiator fan relay. See Figure . Using ohmmeter, check resistance between cavity No. 86 (Dark Blue/Tan wire) in power distribution center for low speed radiator fan relay and terminal No. 55 (Dark Blue/Tan wire) on PCM connector C2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open on Dark Blue/Tan wire between PCM and cavity No. 86 in power distribution center for low speed radiator fan relay. Perform TEST VER-2A .
Ensure low speed radiator fan relay is removed from power distribution center. Using ohmmeter, check resistance between ground and terminal No. 55 (Dark Blue/Tan wire) on PCM connector C2. If resistance is 5 ohms or more, replace PCM. Perform TEST VER-2A . If resistance is less than 5 ohms, repair short to ground on Dark Blue/Tan wire between PCM and cavity No. 86 in power distribution center for low speed radiator fan relay. Perform TEST VER-2A .