Diagnostic Trouble Code Tests and Associated Procedures: 563

Service code 563 indicates a High Speed Electro-Drive Fan (HEDF) circuit failure.

1. Check HEDF relay resistance.

^ With the key off, disconnect the Integrated Relay Control Module (IRCM).

^ Measure resistance between pin 17 and pin 24 at the IRCM.

^ Is the resistance between 50 ohms and 100 ohms?

YES -- Go to step 2.

NO -- Replace the IRCM and retest.

2. Check HEDF circuit continuity.

^ With the key off, disconnect the processor 60 pin connector. Inspect for damaged or pushed out pins, corrosion, and loose wires. Service as necessary.

^ Install a breakout box, leave the processor and IRCM disconnected.

^ Measure resistance between test pin 31 at the breakout box and pin 17 of IRCM vehicle harness connector.

^ Is the resistance less than 5.0 ohms?

YES -- Go to step 3.
NO -- Service open in the HEDF circuit, and retest.

3. Check HEDF circuit for shorts to ground.

^ With the key off, install a breakout box, leaving the processor and IRCM disconnected.

^ Measure resistance between test pin 31 and test pin 40 at the breakout box.

^ Is the resistance greater than 10,000 ohms?

YES -- Go to step 4.

NO -- Service short to ground in HEDF circuit, and retest system.

4. Check HEDF circuit for shorts to power.

^ With the key off, install a breakout box, leaving the processor and IRCM disconnected.

^ Measure resistance between test pin 31 and test pin 37 at the breakout box.

^ Is resistance greater than 10,000 ohms?

YES -- Replace processor, and retest.

NO -- Service short to power, and retest.