Code
P1705
HONDA
P — Powertrain
TCM A/T Gear Position Switch Circuit Shorted
AI status
Completed
Completed
100%
Causes
- Short to battery voltage or ground in the gear position switch wiring
- Damaged, frayed, or chafed harness near the transmission or shift lever
- Corroded, loose, or water-intruded connector at the gear position switch or TCM
- Faulty gear position (range/park/neutral) switch inside the transmission
- Faulty TCM or internal driver circuit
- Aftermarket wiring or jumpers that interfere with the circuit
Symptoms
- Transmission-related MIL (AT light) or check engine light illuminated
- Incorrect or no gear indicator on dash; gear position shown incorrectly
- Vehicle may refuse to start in gear or only start in Park/Neutral
- Transmission stuck in limp/second-gear mode or limited shift functionality
- Intermittent loss of gear position recognition; shifting anomalies
What to check
- Read stored and pending codes and freeze-frame data with a scan tool; note related transmission codes
- Visually inspect wiring and connectors at the transmission/gear position switch and at the TCM for damage, corrosion, or water intrusion
- Wiggle test: with ignition ON (engine off), move wiring and shift lever while monitoring live gear position signal on scan tool
- Check battery voltage and main grounds to ensure stable supply
- Disconnect the gear position switch connector to see if the code clears or changes (use caution; follow manufacturer procedure)
- Inspect for aftermarket accessories or recent repairs that may have disturbed the harness
Signal parameters
- Reference manufacturer service manual for pinout and exact voltages; typical behavior: gear position switch outputs change state as lever moves between positions
- Switch signals commonly referenced to 5 V sensor supply or ground; expect discrete changes (open/closed or 0–5 V transitions) between positions
- With switch disconnected, check for short to battery (constant 12 V) or short to ground at the harness using a multimeter
- Continuity: in specific gear positions selected, continuity should exist between the corresponding terminals; resistance should be low (near 0 Ω) when closed — compare to service data
Diagnostic algorithm
- Step 1: Retrieve P1705 and any related codes (P0705–P0708, etc.), note freeze-frame and current gear state
- Step 2: Perform a visual inspection of the transmission harness, connectors, and TCM connector for damage, corrosion, pin push-out or water entry
- Step 3: With ignition ON (engine off) monitor live gear position feedback on a scan tool and operate the shift lever; confirm whether signal changes match lever position
- Step 4: Backprobe the gear position switch connector and measure reference voltage, signal voltage, and continuity to ground per service manual. Look for shorts to battery or ground
- Step 5: Perform a wiggle test on the harness while watching live data to try to reproduce the fault; repair any damaged wiring or connectors found
- Step 6: Disconnect the gear position switch connector and check whether DTC clears or a different code appears (helps isolate to wiring vs. switch/TCM).
- Step 7: If wiring and switch test good, test or substitute the TCM per manufacturer procedures before replacement
- Step 8: Repair or replace damaged wiring/connectors or the gear position switch as needed, clear codes, and confirm proper operation with a road test
- Safety: secure vehicle (parking brake, chock wheels) and follow OEM procedures when probing connectors or testing circuits
Likely causes
- Wiring damage at the transmission harness or shift cable area (most common)
- Corroded/loose connector at the gear position switch or TCM pin
- Failed gear position switch
- Short to ground from pin chafing against chassis
Fault status
Status
TCM detected a shorted circuit in the automatic transmission gear position (range) switch wiring. TCM may limit transmission operation until the fault is resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email