C1008 — Left Power Running Board Position/Motion Sensor

Will C1008 clear itself?

Sometimes C1008 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How much does it cost to fix C1008?

Control module repair — $300–$1,000; Replace the faulty sensor or actuator — $150–$500; Repair wiring or connectors — $80–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

How do I diagnose C1008 myself?

Start with a scan: confirm C1008, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the sensor and actuator circuits, and verify the suspect component against live data before buying parts.

What is the most common cause of C1008?

The most common causes are: open or shorted wiring in the circuit, control module driver fault, poor ground connection.

What are the symptoms of C1008?

Drivers most often notice: Check Engine Light on, the affected system operates intermittently or not at all, possible limp mode depending on the affected component, increased fuel consumption in some cases.

When your scan tool pulls code C1008, you're dealing with a fault in the power running board system on the left side of the vehicle. This is the motorized step that extends beneath the door when you open it, making it easier to climb in and out of taller trucks and SUVs. The control module logs C1008 when it can't get reliable information from the position or motion sensor that tracks where the step is and whether it's moving properly.

The PCM or body control module won't trigger C1008 based on a single bad reading. It waits for the fault to repeat under specific operating conditions before turning on the check engine light. That's why the problem can seem to come and go. The freeze frame data saved with C1008 is extremely useful — it records engine load, RPM, coolant temperature, and vehicle speed at the exact moment the fault occurred. Use those numbers to recreate the conditions when you're testing.

The position sensor works by tracking the running board through its entire range of travel. Open the door and the module signals deployment; close it and the step retracts. The feedback loop keeps everything synchronized. If that signal goes missing, becomes corrupted, or fails to change when it should, the module sets C1008 and often shuts the system down for safety.

Common Symptoms of C1008

• The check engine light stays on once the fault is confirmed.
• The running board stops working entirely or behaves erratically — deploying partway, stuttering mid-travel, or ignoring door signals.
• Some vehicles enter a reduced-function mode, essentially locking out the feature until the problem is resolved.
• Fuel consumption may climb slightly if a faulty sensor causes excessive cycling of the actuator.
• Limp-home mode is possible on some platforms, though less common with this specific code.

Typical Causes

• A corroded, loose, or physically damaged connector at the harness junction is the most frequent culprit — simple to fix if you catch it early.
• An inadequate ground connection creates the same symptoms by preventing proper circuit completion.
• Open or shorted wiring anywhere in the sensor circuit will trigger C1008 without warning.
• The control module's output driver can fail, though this is comparatively rare.
• The position or motion sensor itself can wear out, sending incorrect or intermittent data back to the module.
• A blown fuse feeding the circuit occasionally gets overlooked during initial troubleshooting.

How to Diagnose C1008

1. Plug in an OBD2 scanner, verify C1008 is stored, and record the freeze frame data before you clear anything — that snapshot tells you exactly what conditions triggered the fault.
2. Look for related diagnostic trouble codes and check manufacturer TSBs for your make and model. Many C0xxx codes have documented factory fixes or software updates that a quick VIN search on the manufacturer site or NHTSA database can reveal.
3. Inspect the wiring harness and connectors feeding the left running board sensor. Pull back the loom and look for chafing, pinched sections, broken strands, or moisture corrosion.
4. At the component connector, verify proper reference voltage, solid ground reference, and clean signal output using a multimeter.
5. Perform a wiggle test on the harness while watching the live data stream — any signal dropouts point directly at broken wires inside the insulation.
6. After any repairs, clear the code and complete a full drive cycle including the conditions from the freeze frame. C1008 should stay cleared if the root cause is fixed.

Repair Options and Costs

The fix depends entirely on which part failed. Here are the typical repair scenarios for C1008, including parts and labor at independent shop rates:

• Wiring or connector repair: $80–$250
• Sensor or actuator replacement: $150–$500
• Control module diagnosis and repair: $300–$1,000

Most shops rate labor at $75–$125 per hour, so simple connector cleaning or a wiring splice falls on the low end while full module replacement pushes toward the top.

Total repair costs for C1008 typically land somewhere between $80 and $1,000. The most expensive scenario is almost never the first thing to check — spend time on accurate diagnosis before buying