DTC P1490-A: Low Speed Fan Control Relay Circuit
NOTE:
For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see
WIRING DIAGRAMS article.
- Using scan tool, actuate low speed fan relay. If low speed fan relay is clicking, go to next step. If low speed fan relay is not clicking, go to step 5.
- Condition to set trouble code is not present at this time. LOW SPEED FAN CONTROL RELAY CIRCUIT DTC sets if an open or shorted condition is detected in low speed radiator fan relay control circuit. Possible causes are: relay coil open or shorted, open fused ignition switch output circuit, low speed radiator fan relay control circuit open or shorted or inoperative circuit driver in PCM. Go to next step.
- Inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, see INACTIVE TROUBLE CODE CONDITION under SELF-DIAGNOSTICS. Test is complete. Perform TEST VER-2A: ROAD TEST VERIFICATION . If related wiring and connectors were repaired, perform TEST VER-2A: ROAD TEST VERIFICATION .
- With actuator test still running, wiggle wiring harness between low speed fan relay and PCM. Low speed fan relay is located in Power Distribution Center (PDC). See Fig 1. If wiggling caused an interruption in low speed fan relay clicking, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-2A: ROAD TEST VERIFICATION . If wiggling did not cause an interruption in low speed fan relay clicking, see INACTIVE TROUBLE CODE CONDITION under SELF-DIAGNOSTICS. Test is complete. Perform TEST VER-2A: ROAD TEST VERIFICATION .
- Disconnect low speed fan relay. Low speed fan relay is located in Power Distribution Center (PDC). Using a 12-volt test light, check voltage on fused ignition switch output circuit at low speed fan relay connector. See Fig 1. See LOW SPEED RADIATOR FAN RELAY CONNECTOR WIRE IDENTIFICATION table. If test light is brightly illuminated, go to next step. If test light is not brightly illuminated, repair open fused ignition switch output circuit. Perform TEST VER-2A: ROAD TEST VERIFICATION .
- Using an ohmmeter, check resistance between low speed fan relay terminals. See Fig 2. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace low speed fan relay. Perform TEST VER-2A: ROAD TEST VERIFICATION .
- Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Using an ohmmeter, check resistance of low speed fan relay control circuit at low speed fan relay connector. See Fig 1. See LOW SPEED RADIATOR FAN RELAY CONNECTOR WIRE IDENTIFICATION table. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in low speed fan relay control circuit. Perform TEST VER-2A: ROAD TEST VERIFICATION .
- Using an ohmmeter, measure resistance of low speed fan relay control circuit between low speed fan relay connector and PCM connector terminal No. 55. See LOW SPEED RADIATOR FAN RELAY CONNECTOR WIRE IDENTIFICATION table and PCM CONNECTOR WIRE IDENTIFICATION table. See Fig 1. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-2A: ROAD TEST VERIFICATION . If resistance is 5 ohms or more, repair open low speed fan relay control circuit. Perform TEST VER-2A: ROAD TEST VERIFICATION .
LOW SPEED RADIATOR FAN RELAY CONNECTOR WIRE IDENTIFICATION
| Terminal | Wire Color | Function |
|---|---|---|
| A | Light Green/Black | Fused Ignition Switch Output |
| B | Red/Light Green | Fused Battery Voltage |
| C | Dark Blue/Pink | Low Speed Radiator Fan Relay Control |
| D | Tan | Low Speed Radiator Fan Relay Output |
PCM CONNECTOR WIRE IDENTIFICATION
| Application | Wire Color | |
|---|---|---|
| PCM Terminal No. 55 | ||
| Low Speed Radiator Fan Relay Control Circuit | Dark Blue/Pink | |