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2007 Chevy TrailBlazer Cold Weather Stalls & Fault Codes P0068, P0036, P0335, P2431 - No Fix for Crankshaft Travel Issue?

Model: 07 Chevy TrailBlazer Fault Code: P0036 Posted: 2016-01-26 20:48

I've owned my 2007 Chevrolet TrailBlazer for three years and am experiencing recurring engine shutdowns and sudden power loss, all of which occur only in cold weather—typically when temperatures drop below 35°F. The vehicle runs perfectly from March through late October, but starts having issues in the colder mornings. The symptoms include: - Complete engine shut-off while driving (I've been able to restart it by dropping into neutral, turning off the key, and re-starting while coasting—this works every time). - Sudden loss of about 50% power; dashboard lights remain on but I can still pull over. The engine eventually stalls. - A brief momentary shutdown followed by normal operation. In each case, the engine often runs with a weak idle or appears 'light' during these events. I've recently pulled several diagnostic trouble codes: P0068 (O2 Sensor 1 Circuit Malfunction), P0036 (O2 Sensor 1 Heater Circuit Malfunction), P0335 (Crankshaft Position Sensor A Circuit Failure), and P2431 (Diesel Particulate Filter Pressure Too High). I've taken the vehicle to the dealer multiple times over the past three years. The latest diagnosis indicates excessive crankshaft travel, leading to wear on the thrust bearing—no repair is available except replacing the entire engine. The dealer suspects this mechanical issue affects the reluctor ring alignment with the crankshaft position sensor (CKP), causing erratic signals. However, I'm confused: why would this only happen in cold weather? I had my CKP replaced about two years ago, along with a MAS AF sensor—both covered under extended warranty. These repairs did not resolve the issue. Given that I'm the original owner and have maintained regular service, I’m hesitant to give up on this vehicle. Current mileage is 135,000 miles. Any insights or suggestions would be greatly appreciated? Is there a possible sensor, wiring, or thermal-related fix instead of a full engine replacement? Thanks in advance.

Related fault codes
P0036P0068P0335P2431
Comments (2)
Anonymous 2016-01-27 08:36

Could this be related to a remote starter system? I'd recommend reviewing the freeze frame data for P0068 and P0335—these codes often point to ignition switch or sensor issues. A quick check of the CKP (Crankshaft Position Sensor) signal might reveal if it's failing intermittently. However, a loss of CKP or CMP should not typically cause engine stalling because the PCM would default to the other sensor for timing control. A lab-grade scanner and oscilloscope are needed to verify exactly what signals the PCM is receiving—this requires hands-on diagnostics with proper equipment.

Anonymous 2016-02-17 08:43

My 2007 TrailBlazer 4.2 had a similar issue: it would start fine until outside temperatures dropped below 42°F, then cranked and died within 2–3 seconds. It ran normally above 45°F. The only code shown was CKPS (Crankshaft Position Sensor). After replacing the sensor, it started properly—but repeated stalling occurred after just a few hours in an unheated garage. I spent the night thinking about this and realized that temperature might be key. I used a low-heat air gun for about 30 seconds, held approximately 6–8 inches from the ECU/ECM on the engine block. After that, it started and ran normally. Over four days of testing, I kept the vehicle warm—no more than two hours cooling off—and it remained stable. I later replaced the ECU/ECM with a unit purchased online and programmed to my specific vehicle. After installing it and running the passlock relearn procedure, the vehicle has been starting and running reliably ever since. Note: I had previously replaced the ignition switch about four months before this issue began. This suggests temperature sensitivity may be tied to sensor or ECU performance in cold conditions. This might help with similar cases involving P0335 and cold-weather stalling.