P07EA

Code

Generic P — Powertrain

Transmission Range Control A Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 23 EN: 39 RU: 25

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Page language: EN

Causes

Damaged or shorted wiring in the Transmission Range Control A signal circuit (short to ground)
Corroded, loose or contaminated connector at the range sensor / PRNDL switch or at the control module
Faulty transmission range sensor / PRNDL switch (internal open or low output)
Blown fuse or lost reference voltage to the range sensor
Poor ground connection related to the transmission range circuit
Faulty PCM/TCM input (less common)

Symptoms

Transmission stuck in one gear, fails to shift, or remains in limp/limitation mode
Incorrect or no PRNDL/gear position displayed on dash
Vehicle may not start (will not crank in gear) if module cannot detect Park/Neutral
Malfunction Indicator Lamp (MIL) or transmission warning lamp illuminated
Intermittent shifting problems or unpredictable gear engagement

What to check

Retrieve and record freeze frame data and additional transmission-related codes with a scan tool
Verify code is current (not historic). Clear codes and attempt to reproduce
Visually inspect wiring and connectors from the range sensor/PRNDL switch to the PCM/TCM for damage, corrosion, pins pushed back, or water intrusion
Verify fuses and power/ground circuits related to transmission control
Backprobe the range sensor connector and measure signal voltage while cycling the shifter
Wiggle harness and shift lever while monitoring signal to check for intermittent faults

Signal parameters

Expected supply/reference voltage: typically 5 V (verify factory spec for vehicle)
Expected signal voltage when low: near 0 V (below ~0.5 V) — code indicates signal below the module threshold
Expected signal when idle/high: depends on sensor type (some sensors output discrete voltages for each gear, others are switches). Compare actual live data to factory values
Typical circuit type: either multi-position potentiometer (analog 0–5 V range) or discrete switch outputs — consult OEM documentation

Diagnostic algorithm

Safety: Park on level ground, key off, engage parking brake and follow vehicle-specific safety procedures.
Read codes: Use a capable scan tool to read P07EA and any related codes; record freeze frame and live PRNDL values.
Visual inspection: Inspect connectors, wiring harness along frame/transmission for chafing, pin corrosion, or water damage.
Check power & ground: With ignition ON, verify the reference (5V) and ground are present at the range sensor connector. Replace fuses or repair grounds if missing.
Measure signal: Backprobe signal wire with DVOM or scope. With ignition ON and shifting through positions, confirm signal changes and note voltage levels. A constant near 0 V indicates a low circuit.
Isolate wiring: If reference and ground present but signal is low, disconnect the range sensor and measure resistance from the signal pin to ground — check for short to ground. Repair wiring if shorted.
Component test: If wiring checks are good, bench-test or replace the transmission range sensor/PRNDL switch per manufacturer procedure and re-test.
Re-scan & road test: Clear codes, verify the fault does not return and that the vehicle shifts and displays gear positions normally.
Control module: If all wiring and sensor checks pass and the issue persists, consider PCM/TCM input fault diagnosis or module reprogramming/replacement per OEM guidance (rare).

Likely causes

Short to ground or broken/abraded wiring between range sensor and PCM/TCM
Corroded/loose connector at the PRNDL switch or harness
Failed transmission range sensor / PRNDL switch
Missing 5V reference or ground due to fuse/ground fault

Fault status

⚠️ Status

Transmission Range Control A circuit low voltage detected (signal below expected threshold). Inspect range sensor/PRNDL wiring, connector, power/ground, and sensor. Replace or repair components as required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours