Code
P1499
PLYMOUTH
P — Powertrain
Open Or Shorted Condition Detected In The Hydraulic Cooling Fan Solenoid Control
Views:
UK: 24
EN: 37
RU: 31
AI status
Completed
Completed
100%
Causes
- Open circuit in solenoid control wiring
- Short to ground or short to battery in control wiring
- Corroded or disconnected connector at the solenoid
- Failed hydraulic fan solenoid (coil open or shorted)
- Blown fuse or bad relay supplying the solenoid
- Faulty PCM/ECM driver output
Symptoms
- Cooling fan does not engage or runs erratically
- Engine overheating or higher than normal operating temperatures
- Reduced A/C cooling performance at idle or low speeds
- Check Engine Light (MIL) illuminated with P1499 stored
- Possible abnormal hydraulic fan noise if partially engaged
What to check
- Read freeze-frame and stored data with a scan tool; verify current/active status
- Visually inspect solenoid connector and wiring for damage, corrosion, or loose pins
- Check related fuses and relays for continuity and proper operation
- Measure supply voltage at the solenoid connector (key ON) and while commanding fan ON with a scan tool or jumper (engine off as appropriate)
- Measure resistance of the solenoid coil (compare to factory spec or note open/short)
- Perform wiggle tests while monitoring voltage/continuity to find intermittent faults
Signal parameters
- Control type: PCM/ECM switched or PWM ground/voltage driver
- Supply voltage to solenoid: battery voltage (approx. 12V) on the feed circuit with key ON
- Control output: switches to ground or applies PWM from PCM — expected to change when commanded
- Solenoid coil resistance: low (single- to low-double-digit ohms) — consult factory specification for exact ohms
- Expected behavior: continuity across coil (not open); no direct short to battery or ground on control feed when solenoid disconnected
Diagnostic algorithm
- Retrieve code(s) and freeze-frame data. Clear codes and see if P1499 returns to confirm active condition.
- Visually inspect the hydraulic fan solenoid connector and wiring harness for damage, chafing, corrosion, or rodent chewing; repair any obvious issues.
- Check fuses and relays for the hydraulic fan circuit; replace any blown fuses or suspicious relays and retest.
- With connector disconnected, measure solenoid coil resistance. If open or shorted (outside factory tolerance), replace the solenoid.
- With key ON (engine off) measure supply voltage at the solenoid power pin; verify battery voltage is present. If power is missing, trace back to fuse/relay and repair.
- Command the solenoid ON using a bidirectional scan tool while monitoring the control pin. If the PCM provides a switching signal but the solenoid doesn't operate, suspect the solenoid or harness between connector and solenoid.
- If no command signal from PCM, back-probe the PCM output and check for short to battery or ground in the harness. Repair wiring as needed.
- If wiring and solenoid test good but code persists and PCM output is nonresponsive or shorted, consider PCM/ECM driver failure — verify with wiring harness isolated and possibly substitute known-good PCM according to manufacturer procedures before replacement.
- After repairs, clear codes and perform road/idle test to confirm proper fan operation and that P1499 does not reappear.
Likely causes
- Pinched or chafed harness near fan or radiator causing intermittent shorts
- Water or corrosion in the solenoid connector
- Solenoid coil internal failure due to heat or contamination
- Missing or blown fuse/failed relay in fan supply circuit
- PCM/ECM damage from previous electrical fault
Fault status
Status
P1499 — Open or short detected in hydraulic cooling fan solenoid control circuit. Check solenoid, wiring, fuses/relays, and PCM output.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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