P0512 on 2014-2016 Jeep Cherokee: Starter Request Circuit Causes and Fixes

What's Unique About the 2014-2016 Jeep CHEROKEE

For the 2014-2016 Jeep Cherokee (KL generation), this code can be more complex than on older vehicles. The starting sequence involves communication between the key fob, the ignition switch (or push-button), the Body Control Module (BCM), the Radio Frequency Hub (RFH), and the PCM. A Technical Service Bulletin (TSB #08-039-16 REV.A) issued for 2014-2016 models shows P0512 appearing alongside network communication codes (U0100, U0131), indicating that the root cause can sometimes be a module communication failure rather than a simple component. The TSB specifically points to a transmission wiring harness that can chafe, causing a no-start or stiff steering feel.

Diagnostic Flowchart

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

Symptoms You May Notice

• Engine does not crank or start.
• Intermittent no-start condition.
• Delayed engine start, may require multiple key turns.
• Clicking noise from the engine bay when trying to start.
• Check Engine Light is illuminated.
• Extended cranking before the engine starts.

Most Likely Causes

1. Defective Starter Relay 🔴 High Probability Relays are electromechanical switches that wear out over time from repeated use and can fail internally due to heat and vibration in the engine bay.
   How to confirm: Locate the starter relays (K1 and K3) in the engine bay fuse box and swap them with an identical relay from a non-critical system (like the horn or blower motor) to see if the vehicle starts. You can also test the relay with a multimeter for continuity and proper function.
   Typical fix: Replace the faulty relay. It's a common, inexpensive part.
   Est. part cost: $10-$30
2. Wiring or Connector Damage (Harness Chafing) 🟡 Medium Probability TSB #08-039-16 REV. A specifically identifies the transmission wiring harness as a potential chafe point on 2014-2016 models, which can cause this code. Wires in the engine bay are also generally exposed to heat and vibration, which can lead to corrosion, chafing, or loose connections over time, especially at the starter solenoid, fuse box, or PCM connectors.
   How to confirm: Visually inspect the transmission wiring harness for any signs of rubbing or damage, as detailed in the TSB. Also, inspect the harness between the fuse box, starter, and PCM for any signs of damage, corrosion, or loose pins. Perform a voltage drop test on the starter request circuit.
   Typical fix: If chafing is found on the transmission harness, repair the wires and install a mastic patch as per the TSB. Otherwise, repair the damaged section of the wiring harness or clean/replace the corroded connector.
   Est. part cost: $5-$100 (depending on the extent of repair)
3. Faulty Ignition Switch or Push-Button Start 🟡 Medium Probability The ignition switch is a high-use component. Internal contacts can wear out, preventing a clean signal from being sent to the control modules. For push-button start systems, this can also involve the key fob transponder or the immobilizer antenna.
   How to confirm: A mechanic can use a scan tool to monitor the ignition switch status in the PCM/BCM data stream. A multimeter can also be used to check for proper voltage output from the switch when activated.
   Typical fix: Replace the ignition switch assembly or relevant immobilizer component.
   Est. part cost: $50-$150
4. Blown Starter Fuse ⚪ Low Probability A fuse blowing typically indicates an underlying electrical problem, such as a short circuit in the starter motor or wiring, which could be related to the harness chafing issue.
   How to confirm: Check the F19 (40A) fuse in the main engine bay fuse box. If it's blown, there is likely a short circuit that needs to be found.
   Typical fix: Replace the fuse after diagnosing and fixing the underlying short circuit.
   Est. part cost: $1-$5

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM) or Body Control Module (BCM): While less common, the control modules (PCM or BCM) that process the start request can fail internally. This is usually the last item to suspect after all other components and wiring in the circuit have been thoroughly tested and confirmed to be good. In some cases, a software update (flash) for the BCM may resolve intermittent no-start conditions on early 2014 models.
• Weak or Dead Battery / Poor Grounds: A battery with insufficient voltage can cause a variety of unpredictable electrical issues and codes, including P0512, because there isn't enough power to properly energize all modules and relays during a start attempt. Similarly, poor or corroded ground connections between the engine, chassis, and battery can create high resistance and prevent a successful start.

Diagnosis Steps

1. Check the battery and charging system. Ensure the battery has at least 12.4 volts and clean, tight terminals and ground connections.
2. Scan for all diagnostic trouble codes. Note any communication (U-prefix) codes, as they strongly point to the wiring harness issue described in TSB 08-039-16 REV. A.
3. Inspect the starter fuse (F19, 40A) in the engine bay fuse box.
4. Locate the starter relays (K1 and K3) in the same fuse box. Swap them with an identical relay from another circuit (e.g., horn) to quickly test if a relay is the cause.
5. Thoroughly inspect the transmission wiring harness for signs of chafing or damage, particularly where it may contact other components. This is the specific issue addressed by TSB 08-039-16 REV. A.
6. If the relays, fuse, and transmission harness are good, have an assistant attempt to start the vehicle while you listen for a 'click' from the starter solenoid. No click suggests the signal is not reaching the starter.
7. Visually inspect the general wiring harness to the starter motor, fuse box, and PCM for any obvious damage, corrosion, or loose connections.
8. Using a multimeter, verify that the starter request signal wire at the PCM is receiving voltage when the ignition is turned to the 'start' position.
9. If no signal is present at the PCM, the problem lies upstream with the ignition switch, Body Control Module (BCM), or related wiring.

Parts You'll Likely Need

• Starter Relay (OEM #68053218AA) — This is the most common and simplest failure point in the starter request circuit. It's an inexpensive and easy part to replace for diagnosis.
  Trusted brands: Mopar, Standard Motor Products, Bosch, Duralast
  OEM price range: $20-$40
  Aftermarket price range: $10-$25
• Ignition Switch — As a high-wear mechanical and electrical part, the ignition switch can fail to send the correct signal to the control modules to initiate starting.
  Trusted brands: Mopar, Dorman
  OEM price range: $100-$180
  Aftermarket price range: $50-$120
• Transmission Wiring Harness — Required if the harness is found to be chafed through, as per TSB 08-039-16 REV. A. In many cases, a simple repair and protection with a mastic patch is sufficient.
  Trusted brands: Mopar
  OEM price range: $200-$400
  Aftermarket price range: N/A

Related Codes That Often Appear With This One

• U0100 — Lost Communication With ECM/PCM. As seen in TSB #08-039-16 REV.A, this code can appear with P0512, suggesting a network or module power/ground issue is the root cause, often related to the chafed transmission harness.
• U0131 — Lost Communication With Power Steering Control Module. Also mentioned in TSB #08-039-16 REV.A, its presence points to a broader vehicle communication problem, potentially caused by the same wiring harness issue affecting the starter circuit.

Technical Service Bulletins (TSBs) & Recalls

• 08-039-16 REV.A: Mentions P0512-00 - STARTER REQUEST CIRCUIT in conjunction with communication DTCs for 2014-2016 models. The bulletin outlines a procedure to inspect and repair or replace a chafing transmission wiring harness that causes the issue.

Platform-Specific Known Issues

• A known Technical Service Bulletin (TSB #08-039-16 REV.A) for 2014-2016 models links P0512 with communication codes U0100 and U0131. The root cause is often a chafed transmission wiring harness, which can lead to a no-start condition or stiff steering. The fix involves inspecting the harness, repairing any damaged wires, and installing a protective mastic patch.

Mechanic-Grade Diagnostic Values

• Main Battery Voltage (Key Off) — expected: Minimum 12.4-12.6 Volts. Failure: Below 12.4V may be insufficient to power all modules correctly during a start attempt, potentially triggering P0512.
• Starter Relay Control Side Voltage — expected: Should read 12V (battery voltage) when the key is turned to the 'START' position.. Failure: No voltage or low voltage indicates a problem with the ignition switch, BCM, or wiring upstream of the relay.
• Starter Relay Coil Resistance — expected: Typically between 60 and 100 ohms (average around 80-85 ohms).. Failure: A reading of infinite resistance (open circuit) or zero resistance (short circuit) indicates a failed relay coil.

Scan Tool Commands That Help

• wiTECH: Reprogram the BCM with the latest software. — For early 2014 models (built on or before July 11, 2014) experiencing an intermittent no-start condition, as per TSB 08-111-14. This TSB addresses software glitches that could cause this symptom.
• wiTECH: Restore BCM Proxi Configuration / Proxi Configuration Alignment — These functions are required after reprogramming (flashing) the BCM to ensure all vehicle modules are communicating correctly with the updated software.

Wiring & Ground Locations

• G905A — Left side of the engine compartment.. This is a major ground distribution point for several components in the engine bay, including the Underhood Power Distribution Center where the starter relays are located. A poor connection here can cause various electrical faults.
• G906A — Lower right front of the engine compartment.. This ground serves components on the right side of the engine. Ensuring all major engine and chassis grounds are clean and tight is a critical step in diagnosing electrical issues like P0512.
• Starter Solenoid Connector — On the starter motor, which is mounted to the engine block near the transmission bell housing.. This is the final connection in the starter request circuit. The signal wire (often a single-pin connector) tells the solenoid to engage the starter. Corrosion or a loose connection here will prevent the starter from cranking.
• PCM Connector — The Powertrain Control Module is located in the engine bay. The starter request signal wire terminates at one of its multi-pin connectors.. This is where the PCM receives the 'start' signal from the BCM/ignition switch. A corroded pin or loose connector here can interrupt the signal and set code P0512.

Real Owner Repair Stories

• YouTube channel 'D.R.I.V.E. Momentum' (2015 Jeep Cherokee) — Intermittent no-start condition. Sometimes it starts, sometimes it doesn't.
  ❌ Tried (didn't work) The owner was experiencing unpredictable starting issues.
  ✅ What actually fixed it The battery terminals were very loose on the battery posts. The voltage would drop to 6-7 volts during a crank attempt. The mechanic installed a new battery and used cotter pins as shims to make the terminals tight on the new battery posts as a temporary repair, which resolved the no-start issue. The underlying problem was a poor connection at the battery.
• Reddit user in r/JeepGrandCherokee (similar platform, relevant issue) (2015 Jeep Grand Cherokee) — Random and infrequent crank-no-start. The engine would just crank and crank but not fire. Tapping on the relays in the fuse box would sometimes allow it to start.
  ❌ Tried (didn't work) Swapping relays around in the fuse box provided a temporary fix but the problem returned.
  ✅ What actually fixed it Another user with the same symptoms reported the final fix was a failing fuel pump that was bleeding pressure out of the line. While this story is for a Grand Cherokee, the symptom of 'crank-no-start' and temporary relief from relay manipulation can point towards a fuel delivery issue rather than the starter circuit itself, making it a valuable counterpoint.

OEM Part Supersession History

• 68237960AA, 68207358AA, 68110952AA → 68053218AA — Part consolidation and revision by the manufacturer.

Model Year Variations Within This Range

• 2014 (built on or before July 11, 2014): These early-build 2014 models may have a BCM software version prone to causing an intermittent no-start condition. TSB 08-111-14 was released to address this by reprogramming the BCM with updated software.