B1627

Code

Other B — Body

PRNDL Reverse Input Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 27 EN: 43 RU: 22

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Page language: EN

Causes

Open or shorted wiring between transmission range sensor (PRNDL) and control module
Corroded, loose or damaged connector at the PRNDL/range sensor or control module
Faulty transmission range sensor (PRNDL switch)
Damaged harness from chafing, water intrusion or rodent damage
Faulty body control module, transmission control module or PCM
Blown fuse or poor ground affecting the circuit

Symptoms

Malfunction Indicator Lamp (MIL) or warning light illuminated
Reverse gear not detected by instrument cluster (PRNDL display incorrect)
Backup lights, backup camera or reverse sensors not operating reliably
Transmission may not shift into reverse or may go into limp/limited mode
Cruise/starting interlocks related to park/neutral may behave incorrectly
Intermittent faults or code returns after moisture or vibration

What to check

Read stored codes and freeze-frame data with a scan tool; note related transmission or communication codes
Visually inspect wiring and connectors at the transmission range sensor and control module for corrosion, damage or water
Check fuses and chassis/engine grounds related to the PRNDL and lighting circuits
Verify reverse lamp operation (if lamps not working, isolate lamp circuit vs PRNDL circuit)
Backprobe the PRNDL reverse input pin at the module and at the sensor while selecting Reverse to observe signal
Perform a wiggle test of wiring while monitoring signal for intermittent changes

Signal parameters

Common expected behavior: a discrete input that changes state when shifter is in Reverse (either pulled to ground or to battery depending on design)
Inactive state: typically near battery voltage or pulled-up level (approx. 10–14 V or vehicle reference voltage) or module reference (e.g., ~5 V) depending on manufacturer
Active (Reverse selected): typically near 0–1 V if switch pulls to ground, or near reference/battery if switch closes to feed
Open-circuit: high impedance / floating or greater than ~10 kΩ between signal and expected reference
Short-to-ground or short-to-battery: verify that voltage is stuck at 0 V or battery voltage regardless of gear selector position

Diagnostic algorithm

Capture codes and date/time/freeze-frame with a scan tool; record any related transmission or communication codes.
Verify symptom: check if reverse lights/camera/cluster change when shifter moved to Reverse and compare to scan tool PRNDL input status.
Perform visual inspection of wiring, connectors and grounds at the transmission range sensor (PRNDL) and control module; repair obvious damage.
With ignition ON (engine off), backprobe the PRNDL reverse input at the module and at the sensor; observe voltage while moving shifter to Reverse. Note expected active/inactive voltage per vehicle design.
If signal does not change, check continuity between sensor pin and module pin. Repair open circuits or corrosion and retest.
If short suspected, disconnect connector at sensor and measure signal at module; if short remains at module, isolate wiring or check for short to power/ground and repair.
If wiring and connectors are good but signal incorrect at sensor, bench-test or replace the transmission range sensor (PRNDL switch).
After repair, clear codes and road-test; verify code does not return and system functions normally.
If fault persists after wiring and sensor replacement, evaluate the control module input circuitry or module communication; consult OEM procedures before module replacement.

Likely causes

Wiring open or short (most common)
Corroded/loose connector at the range sensor or module
Failed transmission range (PRNDL) switch
Water intrusion at connector causing intermittent failures
Control module fault (least likely after wiring/sensor checked)

Fault status

⚠️ Status

PRNDL Reverse Input Circuit Failure — control module detects an open, short or invalid signal for the reverse position. Check PRNDL/range sensor, wiring, connectors, fuses/grounds and module input.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3.0 hours