P0602 on 2007-2014 Chevrolet Silverado 1500: Control Module Programming Error Fixes

What's Unique About the 2007-2014 Chevrolet SILVERADO 1500

For the 2007-2014 Silverado, this code often points directly to an ECM/PCM that needs reprogramming or replacement. The year range covers two distinct generations: the GMT900 (2007-2013) and the K2XX (2014). A key difference appears in the 2014 models, where Technical Service Bulletin #PIT5518 addresses P0602 setting in the Chassis Control Module (CCM) on trucks without the factory trailer brake option, which has a unique fix. This highlights the importance of correctly identifying the module setting the code. Additionally, these trucks are known for having ground connection issues that can cause a variety of electrical faults, including module errors.

Diagnostic Flowchart

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

Generation note: This range covers the second generation (GMT900, 2007-2013) and the first year of the third generation (K2XX, 2014). A specific TSB for P0602 in the Chassis Control Module applies only to 2014 models, showing a key difference between the generations. Grounding points and ECM part numbers also differ between the two generations.

Symptoms You May Notice

• Check Engine Light is on
• Vehicle will not start or is hard to start.
• Engine stalls or idles roughly.
• Reduced engine power ('limp mode').
• Poor acceleration and decreased fuel economy.
• "Service StabiliTrak" or "Traction Control Off" messages on the dash
• Harsh or incorrect transmission shifting.
• "Engine Power Refused" message on the Driver Information Center (DIC).

Most Likely Causes

1. Faulty Engine Control Module (ECM/PCM) 🔴 High Probability Internal memory or processor failure can occur over time due to heat, vibration, and electrical stress, leading to a failed self-check (checksum error). This is the most common ultimate failure for this code.
   How to confirm: After verifying all power/ground connections and attempting a reflash, if the code persists or the module fails to communicate or accept new programming, it is condemned. Often seen with P0601.
   Typical fix: Replace the ECM/PCM. The new module must be programmed with the vehicle's VIN and correct software. Several vendors sell pre-programmed ECMs.
   Est. part cost: $300-$800
2. Corrupted or Failed Software Programming 🟡 Medium Probability Programming can be interrupted by a weak battery, tool disconnection, or an unstable power supply during a reflash attempt. Aftermarket performance tunes can also corrupt the software or cause conflicts, leading to P0602.
   How to confirm: Use a GM-compliant scan tool (like a J2534 device with a GDS2/TIS2Web subscription) to attempt to reprogram the module with the latest factory calibration. If this fixes the issue, the hardware is likely good.
   Typical fix: Successfully reprogram the affected control module. If an aftermarket tune was present, this involves flashing back to the stock GM program.
   Est. part cost: $0
3. Poor Battery Voltage or Bad Grounds ⚪ Low Probability Low voltage during startup or operation can cause modules to fail their internal self-tests. GM trucks of this era are notoriously sensitive to ground issues. 🎬 Watch: How to find and clean common GM ground points. Key locations to inspect include the main engine block to chassis ground strap (often on the driver's side, rear of the engine), battery to frame/radiator support grounds, and smaller grounds on the cylinder heads.
   How to confirm: Test the battery voltage (should be >12.4V at rest), check charging system output (13.7-14.7V), and perform a voltage drop test on all major ground connections from the battery to the frame, engine block, and body. Visually inspect for corrosion or breakage.
   Typical fix: Replace a weak battery or faulty alternator. Clean or replace corroded or broken ground straps. A common failure point is the block-to-chassis ground, which can burn off.
   Est. part cost: $20-$400
4. Incorrect Chassis Control Module (CCM) Installed (2014 Models) ⚪ Low Probability According to TSB #PIT5518, some 2014 trucks not equipped with the factory integrated trailer brake controller (RPO JL1) were misbuilt with a Chassis Control Module. This unnecessary module sets a P0602.
   How to confirm: On a 2014 model, check if the vehicle has RPO code JL1 (Integrated Trailer Brake Controller). If it does not, but a scan tool shows a P0602 stored in the Chassis Control Module (CCM), this TSB applies.
   Typical fix: Remove and discard fuse F19UA from the underhood fuse block as per TSB #PIT5518. This deactivates the unneeded module and resolves the code.
   Est. part cost: $0

Rare But Worth Checking

• Aftermarket Performance Tuner: If a non-factory tune has been loaded onto the ECM, it can cause this code. Returning the ECM to the stock factory program is a necessary diagnostic step. An EFILive forum post discusses how a new module without proper calibration data will throw a P0602 until a valid file is flashed to it.
• Faulty Fuel Pump Control Module (FPCM): While less common, a failing FPCM can sometimes trigger communication codes (like U0109) that are diagnosed alongside ECM codes. In some cases, owners have chased ECM issues when the root cause was the FPCM or its wiring. A YouTube video shows a P0602 being diagnosed in relation to a P069E (FPCM requested MIL), indicating the FPCM had a problem it was reporting to the ECM.
🎬 See a real-world diagnosis of P0602 and P069E codes.

Diagnosis Steps

1. Check and charge the battery. Ensure voltage is stable and above 12.4 volts. A weak battery can cause spurious module errors.
2. Connect a professional-grade scan tool and confirm which module is storing the P0602 code (e.g., ECM, TCM, CCM). Note all other codes.
3. Inspect all major ground connections. On GMT900/K2XX trucks, pay close attention to the battery-to-frame ground, the frame-to-engine-block ground strap (often on the driver's side), and cylinder head grounds. Clean any corrosion and ensure connections are tight.
4. For 2014 models, if the code is in the Chassis Control Module (CCM), check for TSB #PIT5518 applicability. If the truck does not have the factory trailer brake controller (RPO JL1), remove fuse F19UA from the underhood fuse block.
5. Inspect the ECM connectors for corrosion, bent pins, or damage.
6. If the code is in the ECM/PCM, attempt to reprogram (reflash) the module using a J2534 pass-thru device and a valid GM software subscription. This should only be done by a professional with a stable power supply connected to the vehicle.
7. If the reprogramming fails, is interrupted, or the code returns immediately, the control module is internally faulty and must be replaced.
8. Replace the faulty control module. The new module will also require programming to the vehicle's VIN and specific configuration.

Parts You'll Likely Need

• Engine Control Module (ECM/PCM) (OEM #Varies by year/engine. Common GMT900 (2007-2013) part numbers include 12633238, 12654074. Common K2XX (2014) part numbers include 12672537, 12657306, 12704477.) — This is the most common cause of a P0602 code when reprogramming doesn't work. The module's internal memory fails, requiring complete replacement.
  Trusted brands: ACDelco (OEM), CARDONE (Remanufactured), Flagship One (Pre-programmed)
  OEM price range: $450-$800
  Aftermarket price range: $300-$600

Related Codes That Often Appear With This One

• P0601 — This code means "Internal Control Module Memory Check Sum Error," which is another type of internal module fault. They often appear together, pointing strongly to a failed ECM/PCM that needs replacement.
• U-codes (e.g., U0100, U0109) — U-codes indicate a loss of communication between modules. A faulty ECM can stop communicating on the CAN bus, triggering these codes in other modules. A Reddit user reported a U0109 (Lost Communication with FPCM) along with a host of other ECM-related codes when their ECM was failing.

Technical Service Bulletins (TSBs) & Recalls

• PIT5518: Chassis Control Module DTC P0602 With No Other Symptoms / Trailer Brake Controller Wiring Circuit 47 Incomplete
• 05-06-04-060A: Information on Control Module Diagnostic Trouble Code (DTC) P0601, P0602, P0603, P0604, P0606, P062F, P06F3, P1621

Platform-Specific Known Issues

• TSB #PIT5518 for 2014 models: On trucks without the factory Integrated Trailer Brake Control system (RPO JL1), a P0602 may be set by a mistakenly installed Chassis Control Module. The fix is to simply remove fuse F19UA from the underhood fuse block. This TSB also applies to the 2014 GMC Sierra.
• TSB #05-06-04-060A: This is an informational bulletin noting that P0602 is part of a family of internal control module fault codes (P0601, P0603, etc.) that can be set in various modules on various GM vehicles.

Mechanic-Grade Diagnostic Values

• Battery Voltage (engine off) — expected: >12.4 Volts. Failure: Voltage below 12.4V indicates a weak or discharged battery that can cause module glitches.
• Charging System Voltage (engine running) — expected: 13.5V - 14.7V. Failure: Voltage outside this range indicates a faulty alternator or voltage regulator, which can corrupt module memory.
• Voltage Drop on Main Ground Cables — expected: < 0.2 Volts (200 millivolts). Failure: A voltage drop greater than 0.2V indicates high resistance in the ground circuit, which can starve the ECM of a proper ground reference.

Hidden / Shadow Codes Worth Checking

• P0633: Immobilizer Key Not Programmed (see via This code may appear after replacing the ECM, even with a pre-programmed unit. It indicates that the new ECM has not yet learned the vehicle's anti-theft password. A security relearn procedure using a tool with SPS2 access is required to clear it.)

Scan Tool Commands That Help

• GM Techline Connect (SPS2): Service Programming System (SPS2) — This is the official GM software required to flash/reprogram a new or existing ECM, TCM, or other control module. It is used to load the correct VIN-specific calibration file onto the module. Access requires a subscription.
• Professional Scan Tool (e.g., Autel, Snap-on): Crankshaft Position Variation Relearn — This procedure is often required after replacing and reprogramming the ECM to synchronize the new module with the crankshaft position sensor. Failure to perform this may result in a P0315 code and a persistent Check Engine Light.
• GM Techline Connect (SPS2): Immobilizer Learn / Security Relearn — Required after installing a new or used ECM to pair the module with the vehicle's anti-theft system. If not performed, the vehicle may not start and will set a P0633 code.

Wiring & Ground Locations

• G103 — On the front of the right (passenger side) cylinder head on GMT900 models.. This is a primary engine ground. A corroded or loose connection here can cause a host of electrical issues, including intermittent module faults.
• G104 — On the rear of the left (driver side) cylinder head on GMT900 models.. This ground is connected via a strap to the firewall (at G108) and is critical for the engine sensor data and module communication. A loose G104 was identified in a repair video as the cause for a P0601 code.
• G107 — Located on the top left rear of the engine on GMT900 models.. Provides a ground path for various engine components. Like other grounds, it should be inspected for corrosion and tightness.
• G108 — Located on the driver's side firewall, serving as the connection point for the ground strap from the cylinder head (G104).. This body ground is a critical link for the engine's electrical system. A poor connection here can interrupt the ground path for the ECM.
• ECM Connectors (C1/J1, C2/J2) — The ECM is located in the engine bay, typically on the driver's side near the fender or firewall. The connectors are often blue and black/gray.. All power, ground, and communication signals for the ECM pass through these connectors. They should be inspected for corrosion, moisture, and bent or backed-out pins.

Real Owner Repair Stories

• YouTube channel "SuperMarioDiagnostics" (2011 GMC Sierra (similar to Silverado)) — Truck would cut out while driving, setting code P0601. Also had ABS and Service Stabilitrac messages.
  ❌ Tried (didn't work) The technician initially suspected the ECM itself due to the P0601 code.
  ✅ What actually fixed it While wiggling wires with the key on, the technician discovered that disturbing the ground cable at the left rear of the engine (G104) caused the P0601 code to reset. Cleaning this ground connection resolved the issue, demonstrating that a bad ground can mimic a fatal internal module failure.
• PerformanceTrucks.net Forums (2011 Silverado 5.3L) — Truck randomly shuts down while driving, throws P0601 code. Starts back up after waiting a minute.
  ❌ Tried (didn't work) User was considering reflashing the ECM.
  ✅ What actually fixed it The consensus from the forum and the user's plan was that this is a classic symptom of a failing ECM. The final fix is replacing the ECM and flashing the tune back onto the new module.

OEM Part Supersession History

• 12633238 → N/A - This is a widely used service number for GMT900 trucks (approx. 2010-2013). — N/A
  Heads up: This part requires programming to the specific vehicle's VIN. It cannot be swapped directly from another vehicle without being reflashed.
• 12672537 → May be compatible with or superseded by numbers like 12672965, 12676230, 12662034, and 12656993. — Standard part revisions and updates by the manufacturer.
  Heads up: This ECM is for the K2XX platform (2014+). It is not backward compatible with GMT900 (2007-2013) trucks. It also requires VIN programming and may require a security relearn procedure to avoid a P0633 code.

Model Year Variations Within This Range

• 2007-2013 (GMT900): These models use ECMs like the E38 (e.g., part number 12633238). Key ground points are G103 (front passenger head), G104 (rear driver head), and G107/G108.
• 2014 (K2XX): This first year of the new generation uses a different ECM (e.g., part number 12672537). It is subject to TSB #PIT5518 where an unnecessary Chassis Control Module can set P0602, fixed by removing fuse F19UA. The physical location of the ECM is under the battery tray on the driver's side.