P0603 on 2010-2015 GMC Terrain: Keep Alive Memory (KAM) Error Causes and Fixes

What's Unique About the 2010-2015 Gmc TERRAIN

For the 2010-2015 GMC Terrain, GM has issued Technical Service Bulletins (TSBs) acknowledging that code P0603 can appear in multiple modules, including the Transmission Control Module (TCM), and may not always indicate a component failure. TSB #PIP4653E specifically notes that if P0603 is found only in the TCM, a simple reprogram of the module may be the fix. This suggests a higher likelihood that the code is triggered by a simple power interruption—like a battery change—rather than a faulty computer. The battery's location under the PCM also means the PCM is disturbed during a battery replacement 🎬 Watch: Step-by-step guide to replacing the battery and moving the PCM., potentially leading to this code. This is a very common occurrence reported by owners.

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 is on
• Rough or unstable idle
• Hesitation during acceleration
• Transmission may shift erratically or harshly
• Reduced fuel economy
• Difficulty starting the engine or engine stalling
• Illuminated ABS or traction control light in some cases

Most Likely Causes

1. Recent Battery Disconnection or Replacement 🔴 High Probability This is the most common trigger for a KAM error code. On the Terrain, the PCM is located directly above the battery and must be moved to replace it, increasing the chance of a power interruption that sets this code. Many owners report this code appearing immediately after a battery swap.
   How to confirm: Ask the vehicle owner if the battery has been recently replaced, disconnected, or if the vehicle was jump-started. If so, this is the likely cause. The code may appear as "pending" after reconnecting power.
   Typical fix: Clear the code with an OBD-II scanner. The code will likely not return after a few drive cycles as the module relearns adaptive data. No parts are typically needed.
   Est. part cost: $0
2. Weak or Failing Battery 🔴 High Probability A battery that cannot hold a stable charge or drops below the required voltage (typically 12.6V engine off, 13.5-14.5V running) can cause the KAM to lose its memory. This is a frequent point of failure on all modern vehicles with sensitive electronics.
   How to confirm: Test the battery voltage with a multimeter. A healthy battery should read about 12.6 volts with the engine off and 13.5-14.5 volts with the engine running. Most auto parts stores offer free battery testing.
   Typical fix: Replace the vehicle's battery.
   Est. part cost: $150-$250
3. Loose or Corroded Battery Terminals/Grounds 🟡 Medium Probability Corrosion or loose connections at the battery terminals or main chassis ground points can cause intermittent power loss to the control modules. One owner of a 2020 Terrain fixed an intermittent headlight issue by finding and tightening a loose ground bolt on the chassis next to the headlight assembly, demonstrating the sensitivity of these ground points. 🎬 See how to find and fix common GM ground connection issues.
   How to confirm: Visually inspect the battery terminals, cables, and chassis ground straps for corrosion, damage, or looseness. A voltage drop test across the ground connections can confirm high resistance.
   Typical fix: Clean the battery terminals and cable ends with a wire brush. Ensure all connections, including the main engine-to-chassis ground strap, are tight and secure.
   Est. part cost: $5-$20
4. Charging System Malfunction ⚪ Low Probability A failing alternator can produce unstable or insufficient voltage, which can disrupt the KAM and other modules.
   How to confirm: With the engine running, check the voltage at the battery. If it's outside the typical 13.5-14.5 volt range, the alternator is likely faulty. An alternator that is failing may also cause headlights to flicker.
   Typical fix: Replace the alternator.
   Est. part cost: $200-$400

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): While this is the component that logs the code, it is rarely the actual cause. All other power and ground-related issues should be eliminated before considering PCM replacement. GM TSB #05-06-04-060A indicates this code can be set in multiple modules without a hard fault, reinforcing that the module itself is often not the problem.
• Aftermarket Performance Tuner: Installing an aftermarket performance chip or tuner can sometimes interfere with the PCM's memory functions and trigger a P0603 code. This is a more common issue on diesel trucks but can affect any vehicle with a modified ECU program.
• Open or High Resistance in Wiring: A damaged wire or corroded connector in the power supply or ground circuit to the PCM can cause this code. A Reddit user with a P0603 on a different vehicle traced the issue to a corroded wire that had to be bypassed. Another TSB (not for this specific model, but relevant) points to potential high resistance in a communication circuit under the driver's or passenger's sill plate as a cause for module communication issues.

Diagnosis Steps

1. Check if the battery has been recently disconnected or replaced. If so, clear the code and perform a few drive cycles to allow the system to relearn. The code should not return.
2. Inspect the battery terminals and cables for looseness or corrosion. Clean and tighten as needed. Ensure the negative cable connection to the chassis is clean and tight.
3. Using a multimeter, test the battery voltage. With the engine off, it should be approximately 12.6V. With the engine running, it should be between 13.5-14.5V.
4. If battery voltage is low with the engine off, charge the battery and have it load tested. If it fails the load test, replace it.
5. If the running voltage is outside the correct range, test the alternator's output.
6. Inspect the main power and ground connections to the PCM for any signs of damage, corrosion, or looseness. A Reddit user on a G37 with a P0603 was advised to check the specific power supply pin on the ECM 🎬 Watch: How to reset the ECM after addressing power issues. connector for constant voltage.
7. If the code is isolated to the transmission (per TSB #PIP4653E), a TCM reprogram by a dealer may be required.
8. If all power and ground circuits are confirmed to be good and the code consistently returns, the issue may be an internal fault in the PCM, but this is the least likely scenario.

Parts You'll Likely Need

• Car Battery (OEM #ACDelco Gold 48G (or 48AGM for AGM option)) — A weak or failing battery is the most frequent cause of a P0603 code, as it fails to provide the steady voltage required to maintain the Keep Alive Memory. The common BCI group size for this vehicle is H6/48.
  Trusted brands: ACDelco, DieHard, Interstate, X2Power
  OEM price range: $200-$300
  Aftermarket price range: $170-$260
• Battery Terminals — Corroded or damaged terminals create poor connections, interrupting power to the vehicle's modules.
  Trusted brands: Dorman, Standard Motor Products
  OEM price range: $15-$30
  Aftermarket price range: $10-$20

Related Codes That Often Appear With This One

• P0601, P0602, P0604, P0606 — These are all internal control module error codes. GM TSB #05-06-04-060A specifically groups P0603 with these codes, indicating they can be set together across multiple modules due to similar underlying issues like power interruptions.
• P0700 — P0700 is a generic code indicating the Transmission Control Module (TCM) has stored a fault. Since TSB #PIP4653E mentions P0603 can be stored in the TCM and cause shifting concerns, it's plausible to see P0700 alongside it.

Technical Service Bulletins (TSBs) & Recalls

• 05-06-04-060A: Information on control module Diagnostic Trouble Code(s) (DTC)(s) P0601, P0602, P0603, P0604, P0606, P062F, P06F3, P1621 which can be shared in multiple modules.
• PIP4653E: Diagnostic Trouble Codes P0601, P0603, P0604, P062F or P1621 stored in the Transmission Control Module.

Platform-Specific Known Issues

• GM issued TSB #05-06-04-060A as an informational bulletin for technicians regarding P0603 and other related module codes, suggesting it's a known condition that doesn't always mean a failed module.
• TSB #PIP4653E notes that P0603 can be found in the Transmission Control Module (TCM), which may lead to shifting concerns. The recommended fix, if the code is only in the TCM, is to reprogram the module.
• A Reddit user with a 2010 Terrain experiencing shifting issues was told by another owner that their similar problem was resolved by a Body Control Module (BCM) reflash under a recall, as the BCM can affect transmission behavior.

Mechanic-Grade Diagnostic Values

• ECM Keep Alive Memory (KAM) Power Supply Pin Voltage — expected: Constant 12V+ (Battery Voltage), even with key off.. Failure: Any voltage drop or loss of voltage indicates an interruption in the power supply or ground circuit.

Scan Tool Commands That Help

• GDS2 / Tech2: Module Reprogramming — As per TSB #PIP4653E, if code P0603 is stored only in the Transmission Control Module (TCM) and shifting issues are present, a TCM reprogram may be required to resolve the issue after confirming power and grounds are good.

Wiring & Ground Locations

• G103 — Left front of the engine compartment, under the battery tray.. This is a primary ground point for multiple components in the engine bay. A corroded or loose connection here can cause intermittent power issues for various modules, including the ECM.
• G101 — Left front of the engine, on the lower block.. This ground point is specified as a ground for the Engine Control Module and Transmission Control Module. A fault at this specific location can directly interrupt the ground circuit for the modules that set the P0603 code.
• Underhood Fuse Block — Driver's side of the engine bay, next to the brake fluid reservoir.. The main power connections from the battery feed into this block. Loose terminals or internal cracks can cause intermittent power loss to the ECM's KAM circuit. Specific fuses to check for the ECM include F20, F42, F52, F53 and relay R66.
• ECM X1 Connector — On the Engine Control Module itself, which is located above the battery.. This is the main connector providing power and ground to the ECM. Pin 20 (Orange wire) should have constant battery voltage for the Keep Alive Memory. Checking for voltage directly at this pin is the definitive test for the KAM power supply.

Real Owner Repair Stories

• Multiple forum reports (e.g., terrainforum.net, equinoxforum.net) (Various 2010-2015 GMC Terrain and Chevrolet Equinox models) — Check Engine Light with P0603 immediately after battery replacement or jump-start.
  ❌ Tried (didn't work) Worrying about a bad PCM.
  ✅ What actually fixed it Clearing the code with an OBD-II scanner. The code did not return after a few drive cycles, confirming it was only triggered by the temporary power loss during the battery service.
• General Motors technical forums and articles (Various GM models including Terrain/Equinox) — Intermittent stalling, non-start, and multiple electrical codes including P0603, P1682.
  ❌ Tried (didn't work) Replacing the battery., Replacing the alternator., Checking battery terminals.
  ✅ What actually fixed it Discovering and tightening a loose main power or ground connection at the underhood fuse block. The terminals within the block itself can lose tension over time, causing intermittent power disruption to critical relays and modules like the ECM.

Model Year Variations Within This Range

• 2013-2015: For 2013, the optional V6 engine was upgraded from a 3.0L LF1 V6 to a 3.6L LFX V6. This engine change also involved a different Engine Control Module (ECM), potentially with different pinouts and software. While the P0603 diagnostic theory remains the same (check power supply), the specific pins to test for KAM voltage may differ between a 2.4L, 3.0L, and 3.6L model.