B0158 on 2013-2016 Chevrolet Malibu: Causes and Fixes for Ambient Air Temp Sensor

What's Unique About the 2013-2016 Chevrolet MALIBU

This is a well-documented issue on this generation of Chevrolet Malibu and its platform mates like the Buick Regal and Chevy Impala. General Motors has released several Technical Service Bulletins (TSBs) regarding this exact code. The problem is often related to the sensor's exposed location behind the front grille, which makes it and its wiring vulnerable to damage from road debris, minor impacts, or even packed snow. The diagnostic procedure provided by GM is straightforward and points directly to checking the sensor's connection and wiring first.

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 end of the 8th generation (2013-2015 and the 2016 'Malibu Limited') and the start of the 9th generation (2016). The problem, symptoms, and diagnostic approach are identical for both generations as confirmed by GM service bulletins. However, always verify the part number for your specific model year before purchasing.

Symptoms You May Notice

• Outside temperature display on the dashboard or radio is missing, showing dashes ('--'), or a default low reading (like -40°F or -40°C).
• Automatic climate control system does not regulate temperature properly.
• Air conditioning (A/C) may not turn on or blow cold, as the system can't make logical decisions without knowing the outside temperature.
• In some cases, the HVAC temperature settings may default to displaying in Celsius.

Most Likely Causes

1. Faulty Ambient Air Temperature Sensor 🔴 High Probability The sensor is a simple electronic component (a thermistor) that can fail over time due to heat cycles and constant exposure to the elements. It's the most common point of failure.
   How to confirm: After confirming the sensor is connected and wiring is intact, test the sensor's resistance with a multimeter; the resistance should change with temperature. An open circuit (infinite resistance) or short circuit (zero resistance) indicates a faulty sensor. A scan tool showing a fixed, illogical value like -40° also points to a bad sensor.
   Typical fix: Replace the ambient air temperature sensor.
   Est. part cost: $10-$25
2. Damaged Wiring or Connector 🟡 Medium Probability The sensor is located behind the front grille, making its wiring vulnerable to damage from road debris, front-end collisions, or corrosion from water and road salt.
   How to confirm: Visually inspect the wiring harness leading to the sensor for any signs of cuts, abrasions, or corrosion at the connector pins. TSBs specifically mention checking the integrity of circuits 61 and 636 between the sensor and the IPC.
   Typical fix: Repair the damaged section of wire or replace the connector pigtail.
   Est. part cost: $5-$20
3. Disconnected Sensor 🟡 Medium Probability The sensor can be easily knocked loose or forgotten to be reconnected after front-end service, such as bumper, grille, or radiator work. A minor impact with road debris can also be enough to unplug it.
   How to confirm: Visually inspect the sensor, which is typically mounted to the radiator support behind the grille, to see if the electrical connector is unplugged. One owner of a related platform (Chevy Impala) reported the issue started after hitting a raccoon, and the fix was simply finding the dangling connector and plugging it back in.
   Typical fix: Securely reconnect the electrical connector to the sensor.
   Est. part cost: $0

Rare But Worth Checking

• Faulty Instrument Panel Cluster (IPC): The IPC is the module that reads the sensor and sets the code. While extremely rare, an internal failure of the IPC could mimic the symptoms of a bad sensor or wiring. This should only be considered after all other possibilities have been exhausted and confirmed with advanced diagnostics.

Diagnosis Steps

1. Use a scan tool to confirm that B0158 is the only code present in the Instrument Panel Cluster (IPC) module.
2. Check the live data for the 'Ambient Air Temperature' parameter. A reading of -40°F or -40°C is a default value indicating an open or shorted circuit.
3. Visually inspect the area behind the front grille to locate the ambient air temperature sensor, typically mounted on the radiator core support.
4. Check if the sensor's electrical connector is securely plugged in. If not, reconnect it, clear the code, and see if the temperature display returns to normal.
5. If connected, inspect the wiring harness for any visible damage like cuts, chafing, or corrosion on the pins.
6. If wiring appears intact, disconnect the sensor. The IPC sends a 5-volt reference signal to the sensor and measures the voltage drop across the thermistor to determine temperature. An open or short will cause the B0158 code.
7. With the connector unplugged, test the sensor's resistance with a multimeter. The resistance should change with temperature (a thermistor). An open circuit (infinite resistance) or a short (near-zero resistance) confirms a bad sensor.
8. If the sensor tests good, check the two wires in the connector harness (Circuits 61 and 636) for continuity back to the IPC. Check for a 5V reference on one wire and a good ground on the other.
9. If wiring and the sensor are confirmed to be good, the issue may lie with the Instrument Panel Cluster, but this is highly unlikely.

Parts You'll Likely Need

• Ambient Air Temperature Sensor (OEM #25775833) — This sensor is the most common failure point for code B0158. It is an electronic component exposed to the elements that fails over time.
  Trusted brands: ACDelco (GM Genuine), Dorman, Standard Motor Products, NTK
  OEM price range: $15-$25
  Aftermarket price range: $8-$20
• Ambient Air Temperature Sensor Connector Pigtail — If the original connector or wiring is damaged by impact or corrosion, a replacement pigtail is needed to splice into the harness.
  Trusted brands: ACDelco, Standard Motor Products, Dorman
  OEM price range: $20-$40
  Aftermarket price range: $10-$25

Technical Service Bulletins (TSBs) & Recalls

• PIC5656F: Outside Ambient Temperature Display Missing and/or HVAC Temperature Displays in Celsius B0158.
• PIC5656E: Earlier version covering 2013-2015 Malibu and 2016 Malibu Limited.
• PIC5656C: Earlier version covering 2013-2014 Malibu.
• PIC5656B: Earlier version covering 2013 Malibu.

Platform-Specific Known Issues

• GM has issued multiple versions of Technical Service Bulletin PIC5656 (e.g., PIC5656A through PIC5656F) for this issue, which covers the 2013-2016 Malibu and many other GM vehicles. The bulletins consistently guide technicians to check for a disconnected sensor or faulty wiring (circuits 61 and 636) before replacing any parts, highlighting how common the connection issue is.

Mechanic-Grade Diagnostic Values

• Ambient Air Temperature Sensor Resistance — expected: Approx. 10,000 Ohms at 77°F (25°C); Approx. 30,000 Ohms at 32°F (0°C). Resistance increases as temperature decreases.. Failure: Infinite resistance (open circuit) or near-zero resistance (short circuit) at any temperature.
• Scan Tool Live Data - Ambient Air Temperature Sensor Voltage — expected: A voltage between 0.1V and 4.9V that corresponds to the resistance of the sensor.. Failure: Voltage is less than 0.09V or more than 4.90V. A reading of -40°F/°C corresponds to one of these fault conditions.
• Scan Tool Live Data - Cold Start Comparison — expected: On a 'cold-soaked' engine, the Ambient Air Temperature, Intake Air Temperature, and Engine Coolant Temperature should all read within a few degrees of each other.. Failure: If the Ambient Air Temperature reading is significantly different from the other two, the sensor or its circuit is faulty.

Hidden / Shadow Codes Worth Checking

• B0158 02: Outside Air Temperature Sensor Circuit Short to Ground. This indicates the signal wire has a direct or high-resistance path to chassis ground. (see via A GM-specific scan tool like the GDS2 or a high-end professional scanner capable of reading manufacturer-specific body codes and symptom bytes.)
• B0158 05: Outside Air Temperature Sensor Circuit Short to Battery or Open. This indicates the signal wire is open, the ground wire is open, or the signal wire is shorted to a voltage source. (see via A GM-specific scan tool like the GDS2 or a high-end professional scanner capable of reading manufacturer-specific body codes and symptom bytes.)

Scan Tool Commands That Help

• GDS2 (Global Diagnostic System 2): Read DTCs from Instrument Panel Cluster (IPC) — This is the first step recommended by GM TSBs to confirm B0158 is present and to check for any specific symptom bytes (like 02 or 05).
• GDS2 or equivalent professional scan tool: View Live Data > IPC > Ambient Air Temperature — Used to monitor the temperature value being reported to the IPC. A reading of -40° confirms the fault condition and is a crucial diagnostic data point before performing physical checks.

Wiring & Ground Locations

• Circuit 61 — Wire running between the Ambient Air Temperature Sensor and the Instrument Panel Cluster (IPC).. This is the signal wire. The IPC measures the voltage on this circuit to calculate the temperature. A short or open on this wire is a direct cause of B0158.
• Circuit 636 — Wire running between the Ambient Air Temperature Sensor and the Instrument Panel Cluster (IPC).. This is the low reference (ground) wire provided by the IPC for the sensor. An open in this circuit will cause the sensor to read incorrectly and set code B0158.
• G103 — Typically located in the engine compartment on the cowl, above the brake booster.. This is a common ground point for multiple interior modules, including the Instrument Panel Cluster (IPC). While not a direct circuit for the sensor, a poor connection at G103 can cause erratic behavior in the IPC, potentially leading to incorrect readings or codes. It should be checked if other electrical issues are present.

Real Owner Repair Stories

• Reddit user on r/Duramax (Chevy Duramax Truck (similar GM electrical architecture)) — B0158 05 code present, outside temperature display not working.
  ❌ Tried (didn't work) Initial diagnosis pointed towards sensor or wiring.
  ✅ What actually fixed it The owner had recently replaced the A/C control module. The replacement part was for a different trim level that displayed temperature in the rearview mirror, not the dash. The new module was incompatible. Swapping the motherboard from the original module into the new faceplate resolved the issue.

OEM Part Supersession History

• 15035786, 10396844 → 25775833 — Standard part revision and consolidation by the manufacturer.
  Heads up: No known incompatibilities; 25775833 is the correct service replacement for the earlier part numbers on this vehicle.

Model Year Variations Within This Range

• 2016: The 2016 model year includes both the 8th generation 'Malibu Limited' and the new 9th generation design. While the sensor part number and diagnostic theory are the same, the front-end design, sensor mounting location, and wiring harness part numbers (e.g., GM P/N 23258242 for 9th gen) may differ slightly between the two body styles.