Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P1872 — Gearbox potentio.#1 error(SIG.1)

P1872 — Gearbox potentio.#1 error(SIG.1)

Detailed page for trouble code P1872.

33,912codes
59brands
11,451generic
22,461specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P1872

MITSUBISHI P — Powertrain

Gearbox potentio.#1 error(SIG.1)

Brand: MITSUBISHI
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged, corroded or loose connector at the gearbox potentiometer
  • Broken, chafed or shorted wiring between potentiometer and ECU/TCM
  • Failed gearbox position potentiometer (internal wear or contamination)
  • Water/contaminant ingress into sensor or connector
  • Poor ground or reference voltage to the potentiometer
  • Intermittent connection caused by vibration or damaged harness

Symptoms

  • MIL/Check Engine lamp illuminated
  • Erratic or harsh shifting, incorrect gear selection or stuck in one gear
  • Transmission may enter limp/derate mode
  • Gear indicator on dash may be incorrect or jumpy
  • Intermittent fault — symptoms may come and go with vibration or temperature changes

What to check

  • Read and record freeze-frame data and live data for the gearbox potentiometer signal with a scan tool
  • Verify battery voltage is stable (no low-voltage conditions)
  • Visually inspect connector and wiring for damage, corrosion, pin push-out or water entry
  • Backprobe potentiometer connector and measure reference, ground and signal voltages with ignition ON
  • Wiggle test wiring while monitoring live signal for intermittent changes
  • Check continuity and resistance of wiring between potentiometer and TCM

Signal parameters

  • Reference supply typically ~5.0 V (check vehicle spec)
  • Signal output expected to vary smoothly with gear selector movement — commonly in the ~0.5–4.5 V range
  • Signal should not be open (no voltage) or stuck at a rail (0 V or reference voltage)
  • Potentiometer resistance typically changes smoothly as selector moves (manufacturer-specific value, often in kΩ range)

Diagnostic algorithm

  1. Connect a capable scan tool, confirm P1872 and note freeze-frame data; clear code and see if it returns
  2. Visually inspect potentiometer connector and harness at the gearbox for damage, corrosion or contamination
  3. With ignition ON (engine off), backprobe connector: verify reference voltage (≈5 V), ground continuity, and signal voltage; observe while moving gear selector to confirm smooth voltage change
  4. Perform wiggle test on harness and connector while monitoring signal for intermittent faults
  5. If reference or ground missing, trace and repair to TCM power/ground circuits; check fuses and relays if applicable
  6. Measure continuity/resistance between potentiometer and TCM pins; repair any opens/shorts
  7. If wiring and supply are OK but signal behavior is erratic or out-of-range, remove and bench-test or replace the potentiometer
  8. After repair or replacement, clear codes and road-test; confirm proper signal behavior and that the code does not return
  9. If fault persists after harness and sensor replacement, consider TCM/ECU input circuit testing or replacement (refer to service manual)

Likely causes

  • Connector corrosion or loose terminal at the potentiometer
  • Open or short in the wiring harness to the TCM
  • Failed/dirty potentiometer that doesn't change smoothly with gear movement
  • Missing or weak reference voltage/ground to the sensor

Fault status

⚠️ Status
Gearbox potentiometer #1 signal circuit malfunction / signal out of range
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0705 P0706 P0700 P0715 P0720
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1872

Other P — Powertrain

Transmission Mechanical 4-Wheel Drive Axle Lock Lamp Circuit Failure

Brand: Other
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged, corroded or loose connector at the gearbox potentiometer
  • Broken, chafed or shorted wiring between potentiometer and ECU/TCM
  • Failed gearbox position potentiometer (internal wear or contamination)
  • Water/contaminant ingress into sensor or connector
  • Poor ground or reference voltage to the potentiometer
  • Intermittent connection caused by vibration or damaged harness

Symptoms

  • MIL/Check Engine lamp illuminated
  • Erratic or harsh shifting, incorrect gear selection or stuck in one gear
  • Transmission may enter limp/derate mode
  • Gear indicator on dash may be incorrect or jumpy
  • Intermittent fault — symptoms may come and go with vibration or temperature changes

What to check

  • Read and record freeze-frame data and live data for the gearbox potentiometer signal with a scan tool
  • Verify battery voltage is stable (no low-voltage conditions)
  • Visually inspect connector and wiring for damage, corrosion, pin push-out or water entry
  • Backprobe potentiometer connector and measure reference, ground and signal voltages with ignition ON
  • Wiggle test wiring while monitoring live signal for intermittent changes
  • Check continuity and resistance of wiring between potentiometer and TCM

Signal parameters

  • Reference supply typically ~5.0 V (check vehicle spec)
  • Signal output expected to vary smoothly with gear selector movement — commonly in the ~0.5–4.5 V range
  • Signal should not be open (no voltage) or stuck at a rail (0 V or reference voltage)
  • Potentiometer resistance typically changes smoothly as selector moves (manufacturer-specific value, often in kΩ range)

Diagnostic algorithm

  1. Connect a capable scan tool, confirm P1872 and note freeze-frame data; clear code and see if it returns
  2. Visually inspect potentiometer connector and harness at the gearbox for damage, corrosion or contamination
  3. With ignition ON (engine off), backprobe connector: verify reference voltage (≈5 V), ground continuity, and signal voltage; observe while moving gear selector to confirm smooth voltage change
  4. Perform wiggle test on harness and connector while monitoring signal for intermittent faults
  5. If reference or ground missing, trace and repair to TCM power/ground circuits; check fuses and relays if applicable
  6. Measure continuity/resistance between potentiometer and TCM pins; repair any opens/shorts
  7. If wiring and supply are OK but signal behavior is erratic or out-of-range, remove and bench-test or replace the potentiometer
  8. After repair or replacement, clear codes and road-test; confirm proper signal behavior and that the code does not return
  9. If fault persists after harness and sensor replacement, consider TCM/ECU input circuit testing or replacement (refer to service manual)

Likely causes

  • Connector corrosion or loose terminal at the potentiometer
  • Open or short in the wiring harness to the TCM
  • Failed/dirty potentiometer that doesn't change smoothly with gear movement
  • Missing or weak reference voltage/ground to the sensor

Fault status

⚠️ Status
Gearbox potentiometer #1 signal circuit malfunction / signal out of range
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

P0705 P0706 P0700 P0715 P0720
6,682

The library contains 6,682 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

AUDI
1,160
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
86
LAND ROVER
320
LEXUS
1
LINCOLN
166
MERCEDES-BENZ
703
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
58
TOYOTA
2,042
TRIUMPH
131
VOLKSWAGEN
139
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .