U1424 on 2015-2017 Ram ProMaster City: Implausible Engine Torque Signal Fixes

What's Unique About the 2015-2017 Ram PROMASTER CITY

What's unique to the ProMaster City is that Ram has officially acknowledged this issue through specific Technical Service Bulletins (TSB #18-063-17 REV. A and #18-064-17). These TSBs directly point to a software glitch within the Powertrain Control Module (PCM) as the root cause, where the original calibration was too sensitive. This makes the diagnostic process more straightforward than on other vehicles, as the first and most effective step is a dealer-performed software reflash rather than immediately suspecting a hardware failure. The vehicle itself is a rebadged Fiat Doblò produced in Turkey for the North American market.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light (Malfunction Indicator Lamp, MIL) is on.
• Vehicle may enter 'limp mode' with reduced power and speed.
• Erratic, harsh, or delayed transmission shifting.
• Inability to shift, or getting stuck in one gear until the vehicle is restarted.
• Electronic Stability Control (ESC) or throttle control warning lights may illuminate simultaneously.

Most Likely Causes

1. Outdated Powertrain Control Module (PCM) Software 🔴 High Probability → Shop Engine Control Module (ECM) This is a known issue documented by Ram in TSB #18-063-17 REV. A and #18-064-17, which specifically call for a software update to resolve the code by correcting the PCM's sensitive logic.
   How to confirm: A Ram dealership can check the current software calibration level of the PCM using a wiTECH scan tool and compare it to the latest version specified in the TSB. The wiTECH topology view will show if modules have available flash updates.
   Typical fix: Reprogramming (flashing) the PCM with the latest software version. This must be done by a dealer or a well-equipped independent shop. The TSB also notes that the TCM should be checked for updates and a 'TCM Quick Learn' procedure may be required after the flash.
   Est. part cost: $0
2. Failing Camshaft or Crankshaft Position Sensor 🟡 Medium Probability → Shop Engine Crankshaft Position Sensor These sensors provide critical engine speed and position data for torque calculation. An erratic signal from a failing sensor can cause the PCM to send implausible data to the TCM. TSB #18-063-17 REV. A explicitly lists DTCs P0335 (crankshaft) and P0340 (camshaft) as related faults addressed by the software update, indicating a strong link. There is also a separate TSB related to premature camshaft position sensor failure on the 2.4L engine.
   How to confirm: Scan for additional trouble codes, specifically P0335 (crankshaft sensor) or P0340/P0365 (camshaft sensors), which often accompany U1424 when a sensor is the root cause. P0340 typically points to the intake camshaft sensor, which is difficult to access under the intake manifold. A functional test involves back-probing the sensor's signal wire to see if the voltage switches between ~5V and 0V as the engine is rotated.
   Typical fix: Replace the faulty sensor. It's often recommended to use OEM Mopar parts for these critical sensors to ensure reliability. The OEM part number for the camshaft position sensor has been superseded multiple times, with the latest being 68080819AD. 🎬 Watch: How to locate and replace the camshaft position sensor. The OEM crankshaft position sensor is part number 68079375AD (replaces 68079375AB/AC). 🎬 See this walkthrough for replacing the crankshaft position sensor.
   Est. part cost: $40-$110
3. Wiring Harness or Connector Issues ⚪ Low Probability While less common, corrosion or damage to the wiring between the PCM and TCM can corrupt the communication signal. The main PCM connectors on the firewall can be a point of water intrusion, leading to intermittent issues. A critical ground strap runs from a starter mounting bolt to the vehicle's frame; corrosion here can cause issues.
   How to confirm: Visually inspect the wiring harnesses and connectors for any signs of damage, corrosion, or loose pins, particularly at the PCM, TCM, and sensor connectors. Test the sensor connector for 5V power, proper ground (<0.1V), and signal integrity.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the corroded connector.
   Est. part cost: $10-$50

Rare But Worth Checking

• Failing Powertrain Control Module (PCM) or Transmission Control Module (TCM): → Shop Engine Control Module (ECM) This is rare and should only be considered after all other possibilities, including the software update and wiring checks, have been exhausted. A module failure is a last resort diagnosis.
• Weak or Failing Battery: Low system voltage during startup can cause unpredictable communication errors between modules. If the battery is old or weak, it can be a simple but overlooked cause of network codes like U1424. Normal voltage with the engine off is around 12.1-12.4V; when running, it should be near 14V.

Diagnosis Steps

1. Check for Technical Service Bulletins (TSBs). For this vehicle, TSB #18-063-17 REV. A (for 2015-2016) or #18-064-17 (for 2017) is the most important first step.
2. Scan for all stored DTCs. Note any accompanying codes like P1DD2, U0402, or sensor-related codes (P0335, P0340, etc.). Prioritize diagnosing the root cause of any other engine codes first, as U1424 is often a secondary code.
3. If TSB #18-063-17 REV. A or #18-064-17 applies and has not been performed, have a Ram dealer update the PCM software. This is the most likely fix. The TSB also recommends verifying the TCM has the latest software.
4. If the software is already up-to-date, investigate any other codes present, especially for crankshaft or camshaft sensors. Test the sensor circuits and replace the sensor if it is faulty.
5. If no other codes exist, perform a thorough visual inspection of the wiring harness and connectors between the PCM and TCM for any signs of damage, corrosion, or looseness.
6. Check battery health and system voltage. A weak battery can cause various communication faults.
7. If the wiring and battery are intact, advanced diagnostics may be needed to test the PCM and TCM, which typically requires professional-level tools.

Parts You'll Likely Need

• Powertrain Control Module (PCM) Software Update — This is not a physical part, but a software reflash is the official manufacturer-recommended fix to correct the logic that triggers code U1424 on this vehicle. The cost is typically one hour of dealer labor.
  OEM price range: $150-$250
  Aftermarket price range: N/A
• Camshaft Position Sensor (OEM #68080819AD (supersedes 68080819AC, 68080819AB, 5033308AB)) — A common hardware failure that can cause this code if the PCM software is already up-to-date. The 2.4L engine uses two of these sensors.
  Trusted brands: Mopar, Delphi, NGK/NTK, Standard Motor Products
  OEM price range: $85-$130
  Aftermarket price range: $30-$70
• Crankshaft Position Sensor (OEM #68079375AD (supersedes 68079375AC, 68079375AB)) — Another common hardware failure point that provides essential data for torque calculation. A faulty sensor can directly trigger U1424.
  Trusted brands: Mopar, Delphi, Dorman
  OEM price range: $80-$120
  Aftermarket price range: $40-$75

Related Codes That Often Appear With This One

• P1DD2-00 — This code, 'Torque Request Signal From TCM Denied', is the PCM's side of the story. The PCM denies the TCM's request, and the TCM then logs U1424. They are directly linked and mentioned together in TSB 18-063-17 REV. A.
• U0402 — Meaning 'Implausible Data Received From TCM', this is another network code that indicates a communication breakdown between the two modules and is also cited in the same TSB.
• P0335 / P0339 — These codes for the crankshaft position sensor circuit can be the root cause of the implausible torque signal.
• P0340 / P0365 — These codes for the camshaft position sensors ('A' and 'B') can also be the root cause of the implausible torque signal.

Technical Service Bulletins (TSBs) & Recalls

• 18-063-17 REV. A: For 2015-2016 models, this TSB directly addresses U1424 by recommending a PCM software update. It also lists P1DD2-00, U0402, P0335, and P0340 as related codes fixed by the same flash.
• 18-064-17: For 2017 models built before mid-June 2017, this TSB provides similar powertrain diagnostic and system improvements via a PCM software update, specifically targeting U1424, U0402, and P1DD2.

Platform-Specific Known Issues

• TSB #18-063-17 REV. A was issued by Ram specifically for 2015-2016 ProMaster City models to address this code, along with over a dozen others, via a PCM software update. The update also includes other enhancements for catalytic converter operation and A/C clutch cycling.
• TSB #18-064-17 was issued for 2017 models built on or before June 13, 2017, providing a similar PCM software update for U1424, P1DD2-00, and U0402.

Mechanic-Grade Diagnostic Values

• Cam/Crank Sensor 3-Wire Functional Test — expected: Signal wire voltage should switch between ~5V and 0V when a metal object is passed in front of the sensor tip (or when the engine is manually rotated).. Failure: Voltage is stuck high or low and does not switch, indicating a dead sensor.
• Camshaft/Crankshaft Position Sensor Power Supply — expected: Approximately 5V with key on, engine off.. Failure: 0V indicates an open in the supply wire from the PCM; voltage significantly below 5V suggests a wiring issue.
• Camshaft/Crankshaft Position Sensor Ground Circuit — expected: Near 0V (less than 0.1V) when testing between the ground pin and a known good ground.. Failure: Voltage reading above 0.1V indicates high resistance or a poor ground connection.
• General System Voltage — expected: Around 12.1V - 12.4V with engine off. Should rise to 13.7V - 14.4V when the engine is running.. Failure: Voltage stays near 12V when running, indicating the alternator is not charging. Persistently low voltage can cause random communication codes.

Scan Tool Commands That Help

• wiTECH or equivalent professional scanner: TCM Quick Learn — This procedure should be performed after a PCM/TCM software update, transmission replacement, or sometimes after a battery disconnect. It resets and relearns the transmission's clutch fill volumes and shift points to resolve harsh or erratic shifting.
• wiTECH: Update Controller Software — This is the primary repair for code U1424 as specified by Ram TSBs #18-063-17 and #18-064-17. It flashes the PCM with a new calibration to correct overly sensitive logic.
• wiTECH: Network Topology View — This is a diagnostic view, not a command. It provides an at-a-glance color-coded map of all vehicle modules, showing which have DTCs and, crucially, which have available software updates (flashes), streamlining diagnosis.

Wiring & Ground Locations

• Engine Ground Strap — One critical ground path runs from a starter mounting bolt to the vehicle's frame.. A poor engine ground can cause erratic sensor readings and communication errors between the PCM and TCM, leading to network codes like U1424.
• Intake Camshaft Position Sensor Connector — On the intake camshaft position sensor, located under the intake manifold. It is a 3-pin connector.. This is the primary connection point for testing the sensor. Pin 1 is the 5V power supply, Pin 2 is the signal wire, and Pin 3 is the ground. Verifying signal integrity here is a key diagnostic step for a related P0340 code.

Real Owner Repair Stories

• Reddit user Mcdw83 in r/AskMechanics (2016 Ram 1500 3.6L V6 with 160k miles (engine family related to the 2.4L)) — Randomly going into limp mode with check engine light and traction control light on. Codes P0365, U1424, and P1DD2 were present.
  ❌ Tried (didn't work) Replacing only one camshaft position sensor., Replacing the battery (this provided a temporary fix for about 3 weeks before issues returned).
  ✅ What actually fixed it Replacing the second camshaft position sensor. The owner realized that after replacing the first sensor, the camshaft code (P0365) was still present but for a different bank, indicating both original sensors had failed.

When the Usual Fixes Don't Work

• While a PCM software update is the most common fix, it is not a guaranteed solution. In one documented case involving U1424 and related sensor codes, the owner had to replace both camshaft position sensors to finally resolve the issue, as both had failed independently. This highlights that underlying hardware faults can still be the root cause even when a software issue is known to exist.

OEM Part Supersession History

• 5033308AB, 68080819AB, 68080819AC → 68080819AD — Standard part revision and improvement by the manufacturer.
  Heads up: The newest part number (68080819AD) is the correct replacement for all previous versions for this application.

Model Year Variations Within This Range

• 2017: The TSB for the 2017 model year (#18-064-17) applies specifically to vehicles built on or before June 13, 2017. Vehicles built after this date should already have the updated PCM software from the factory.