B1156 Diagnostic Trouble Code

B1156 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a B1156 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
Cherry red hot catalytic converter

Possible Causes :

Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Repair Processes :

With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code B1156 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before B1156.

Fortunately, B1156 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

B1156 Trouble Code For Specific Cars

B1156 Jaguar Xj-8l Seat Driver Occupied Input Circuit Open
B1156 Plymouth Gtx Evaporative Emission Control System Purge Control Valve Circuit Shorted
B1156 Daimler Majestic Heated Backlite Input Circuit Short To Ground
B1156 Samsung Sm7 Illuminated Entry Relay Circuit Open
B1156 Mitsubishi Mirage Aux A/C Control Switch Reference Circuit Short to Battery
B1156 Aston Martin Mark Ii Air Suspension Vent Solenoid Output Circuit Failure
B1156 Vauxhall Zafira A Pressure Transducer Redundant / Secondary Signal Faulted