Transmission Range Sensor A Circuit Range/Performance
The transmission range sensor (which includes the neutral safety switch) is reporting a signal outside its expected range or performance parameters. This prevents the PCM from accurately detecting what gear the transmission should be in, potentially allowing the vehicle to start in gear or forcing the transmission into limp mode with severely reduced power.
What You Might Notice
- Vehicle may start in gear and lurch forward unexpectedly
- Transmission forced into limp mode with significant power loss
- Lack of power especially from a complete stop
- Check Engine light illuminated
- Difficulty shifting or erratic transmission behavior
Most Common Causes
- 1
Faulty transmission range sensor
The sensor itself is malfunctioning or providing out-of-range voltage signals to the PCM. This is the most common cause of this code.
- 2
Wiring or connector issues
Corroded, loose, or damaged wiring and connectors between the transmission range sensor and PCM can cause intermittent or invalid signals.
- 3
Neutral safety switch failure
The integrated neutral safety switch component of the transmission range sensor has failed, preventing proper gear position detection.
- 4
PCM or transmission control module malfunction
The engine control computer may be faulty and unable to properly interpret valid sensor signals, though this is less common than sensor failure.
How to Diagnose It
- 1
Check Faulty transmission range sensor — The sensor itself is malfunctioning or providing out-of-range voltage signals to the PCM. This is the most common cause of this code.
- 2
Check Wiring or connector issues — Corroded, loose, or damaged wiring and connectors between the transmission range sensor and PCM can cause intermittent or invalid signals.
- 3
Check Neutral safety switch failure — The integrated neutral safety switch component of the transmission range sensor has failed, preventing proper gear position detection.
- 4
Check PCM or transmission control module malfunction — The engine control computer may be faulty and unable to properly interpret valid sensor signals, though this is less common than sensor failure.
How to Fix It
- 1
Replace transmission range sensor
Remove and install a new transmission range sensor assembly, which includes the neutral safety switch. This is the most common repair for this code.
- 2
Inspect and repair wiring/connectors
Check all wiring harnesses and connectors between the transmission range sensor and PCM for corrosion, damage, or loose connections. Clean or replace as needed.
- 3
Check PCM for faults
If sensor and wiring are confirmed good, have the PCM tested or reprogrammed by a professional technician, as it may need updating or replacement.
- 4
Verify transmission fluid level
Low or dirty transmission fluid can affect sensor operation. Check fluid level and condition, topping off or performing a fluid change if necessary.
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