P0615 on 2020-2022 Ram 1500: Starter Control Circuit Causes and Fixes

What's Unique About the 2020-2022 Ram 1500

For the 5th generation Ram 1500 (2019+), the starting system is fully integrated into the truck's complex electronics. Unlike older vehicles, a simple mechanical key turn doesn't directly power the starter. Instead, it's a request to the PCM, which checks various conditions before activating the starter relay located in the under-hood fuse box (Power Distribution Center). This makes the system more prone to electrical faults, such as wiring issues or relay failures, rather than just a bad starter motor, a fact corroborated by a manufacturer Technical Service Bulletin (TSB) for this exact issue.

Diagnostic Flowchart

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

Symptoms You May Notice

• Engine will not crank or start.
• Intermittent no-start condition, sometimes worse when the engine is cold.
• A single audible 'click' from the engine bay when trying to start.
• Illuminated Check Engine Light.

Most Likely Causes

1. Faulty Starter Relay 🔴 High Probability Relays are electromechanical switches with a finite lifespan and are a common failure point in many modern vehicles. They are exposed to heat and vibration in the engine bay.
   How to confirm: Locate the starter relay in the under-hood fuse box. You can often swap it with an identical relay from a non-essential system (like the horn) to see if the truck starts. If it does, the relay is bad.
   Typical fix: Replace the starter relay.
   Est. part cost: $20-$50
2. Wiring or Connector Issue 🟡 Medium Probability The TSB for this code points to a 'Circuit Open' condition, which is frequently caused by a break, corrosion, or loose connection in the wiring harness between the PCM, the relay, and the starter solenoid. 🎬 Watch: Diagnosing common no-crank issues on 2018-2020 models. [S2208000113, 2] Wires can chafe against the frame or engine components over time.
   How to confirm: Visually inspect the wiring harness for any signs of damage, chafing, or corrosion, especially near the starter motor and fuse box. Perform a 'wiggle test' by gently moving sections of the harness while an assistant tries to start the engine; if it suddenly cranks, you've found the problem area. Use a multimeter to check for continuity and proper voltage at the starter relay socket and the starter solenoid signal wire when the start button is pressed.
   Typical fix: Repair the damaged section of wire or replace the corroded connector.
   Est. part cost: $10-$100
3. Failed Starter Motor or Solenoid 🟡 Medium Probability
   How to confirm: After confirming the starter relay and wiring are good, check for voltage at the starter solenoid's small signal terminal while an assistant tries to start the engine. If 12V is present but the starter does not engage, the starter motor/solenoid assembly has failed. Some owners report this failure is intermittent and more likely to occur when the engine is cold.
   Typical fix: Replace the starter motor assembly.
   Est. part cost: $250-$500

Rare But Worth Checking

• Blown Fuse: Always a quick and easy check. Inspect the fuses related to the starting and ignition circuits in the fuse box.
• Faulty Powertrain Control Module (PCM): This is rare and should only be considered after all other possibilities (wiring, relay, starter) have been definitively ruled out. The PCM's internal driver for the starter circuit can fail.
• Weak or Dead Battery: While not a direct cause of a circuit fault code, a weak battery can cause a variety of strange electrical issues and prevent the starter from having enough power to crank. Voltage should be above 12.4V at rest.

Diagnosis Steps

1. Check the battery voltage to ensure it is above 12.4 volts and that the terminals are clean and tight.
2. Scan the vehicle for any other trouble codes that may be present.
3. Locate the starter relay in the under-hood fuse box. Try swapping it with a known good, identical relay (e.g., from the horn circuit) to see if the engine starts.
4. If the relay is not the issue, inspect the starter circuit fuse.
5. Visually inspect the wiring harness between the fuse box and the starter motor for any obvious signs of damage, corrosion, or loose connections. Perform a 'wiggle test' on the harness while attempting to crank.
6. Using a multimeter, check for power at the control side of the starter relay socket when the ignition is turned to 'START'.
7. If power is present at the relay socket, proceed to the definitive test: check for 12V at the starter solenoid's small signal wire when attempting to crank the engine.
8. If 12V is present at the solenoid but the engine doesn't crank, the starter motor is faulty.
9. If 12V is NOT present at the solenoid, there is an open circuit in the wiring between the relay and the starter.
10. If there is no power at the relay's control circuit, the issue lies upstream with the ignition switch, neutral safety switch, or the PCM itself.

Parts You'll Likely Need

• Starter Relay (OEM #68405980AA, 4727370AA (Verify with VIN)) — This is the most common and least expensive failure point in the starter control circuit.
  Trusted brands: Mopar, Bosch, Standard Motor Products
  OEM price range: $30-$60
  Aftermarket price range: $15-$40
• Starter Motor (OEM #68441792AA (for 5.7L V8, verify with VIN)) — If the relay and wiring are confirmed to be good, the starter motor assembly itself is the next likely culprit.
  Trusted brands: Mopar, bproauto (Mopar-backed), Denso, Bosch
  OEM price range: $400-$600
  Aftermarket price range: $250-$500

Technical Service Bulletins (TSBs) & Recalls

• S2208000113: Addresses a 'No Start, DTC P0615 Starter Control Circuit Open' condition on 2020 models.

Platform-Specific Known Issues

• A Technical Service Bulletin (TSB #S2208000113) was issued for the 2020 model year specifically for a no-start condition accompanied by DTC P0615, confirming this is a recognized issue by the manufacturer.
• Owners on forums report intermittent no-start conditions that are more prevalent when the engine is cold. The symptom is a single 'click' when trying to start, but it may start successfully after multiple tries or once warmed up. This points to 🎬 Watch: Troubleshooting a click or no-start on your Ram 1500. a component with high resistance when cold, like the starter motor or a poor connection.

Mechanic-Grade Diagnostic Values

• Starter Relay Coil Resistance — expected: 75 ± 5 ohms. Failure: A reading outside this range indicates a faulty relay.
• Starter Relay Control Circuit (T752) Resistance — expected: Below 5.0 Ohms. Failure: A resistance above 5.0 Ohms indicates an open in the circuit between the PCM and the TIPM/PDC.
• Starter Solenoid Coil Resistance — expected: 0.2 to 0.8 ohms (general automotive). Failure: A significantly higher reading (e.g., 4 ohms or more) or an open circuit (OL) suggests a damaged solenoid coil.
• Voltage at Starter Relay Control Terminal — expected: 5V - 12V when start button is pressed. Failure: No voltage indicates an issue upstream, potentially with the PCM or ignition switch.
• Ground Circuit Continuity — expected: < 0.1 Ω. Failure: Higher resistance indicates a poor ground connection, which can trigger the code.

Scan Tool Commands That Help

• Techstream (or equivalent professional scanner): Active Test: Control the Starter Relay — This bidirectional command allows a technician to manually command the starter relay ON and OFF through the scan tool. If the relay clicks and the starter engages via the scan tool command but not with the key/button, it helps isolate the problem to the ignition switch or its input to the PCM, rather than the PCM output or the relay itself.

Wiring & Ground Locations

• T752 Circuit — Wiring between the Powertrain Control Module (PCM) C3 connector and the Power Distribution Center (PDC/TIPM) C1 connector.. This is the specific 'Starter Relay Control Circuit' referenced by the P0615 code. An open or short in this wire is a direct cause of the fault.
• PDC Connector C5, Pin 7 — Under the main Power Distribution Center (under-hood fuse box).. This is the F781 circuit, a Run/Accessory feed from the PDC. While not the primary starter control, issues in related power feeds from the PDC can cause various electrical faults.
• PDC Connector C7, Pin 5 — Under the main Power Distribution Center (under-hood fuse box).. This is the W880 circuit, a selectable Run/Accessory or Battery feed. Problems with power distribution from the main fuse box are a key area to investigate for electrical codes.
• Engine Ground Strap — Typically a braided strap running from the engine block/cylinder head to the vehicle's frame or firewall.. A poor or broken engine ground can cause a voltage drop across the entire electrical system, especially during high-current draws like starting. The PCM can interpret this as a circuit fault, potentially triggering P0615 even if the starter circuit components are good.

Real Owner Repair Stories

• Reddit user on r/ram_trucks (Ram 1500 (year not specified, but modern)) — No crank, no start. All accessories work. P0615 code is present.
  ❌ Tried (didn't work) Battery tested good., Starter relay and fuse tested good., Reseated all connections at the TIPM (fuse box) and PCM.
  ✅ What actually fixed it The user confirmed the starter motor itself was good by jumping it directly from the battery. The final diagnosis was that the starter relay socket in the fuse box was not receiving the power signal from the ignition, indicating a wiring break or a fault within the TIPM/PDC itself.

OEM Part Supersession History

• 6106574AA, 6106575AA, 6106577AA, 68094365AA → 68405980AA — Part consolidation and revision by Mopar.