B1004 Engine Trouble Code
What is B1004?
B1004 code can indicate a faulty oxygen sensor, which may eventually damage the catalytic converter (repair cost: $2,000–$2,200). Professional diagnosis costs around $200–$210. Oxygen sensors are often straightforward to replace — check your owner's manual for location and instructions. This issue should be addressed promptly to prevent further damage.
Code Information
| Code Type: | OBD-II Body (B) Trouble Code |
| System: | Body |
| Code: | B1004 |
B1004 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
B1004 Code Structure
Understanding what each digit means in the B1004 body trouble code:
| B | 1 | 0 | 0 | 4 |
|---|---|---|---|---|
| Body Code | Fuel And Air Metering | Ambient Air Temperature Sensor Circuit Low | Cold Start Injector 1 Malfunction | Timing Reference High Resolution Signal A Too Many Pulses |
How to Fix B1004
Diagnostic Steps:
Regarding B1004, carefully inspect the wire harness near the intake manifold bracket, best accessed from below near the oil filter. Look for chafing, pinching, or damaged insulation.
Repair Solution:
Firing order is engineered to minimise vibration. Altering firing order results in mistimed ignition and poor engine operation. Consult vehicle-specific repair manual for correct firing order.
Technical Notes:
B1004 on electronically controlled automatic transmissions relates to shift solenoid operation. The solenoid actuates hydraulic circuits controlling clutches or bands for gear changes.
B1004 Description
B1004 engine trouble code is related to Timing Reference High Resolution Signal A Too Many Pulses.
Main Cause
The primary reason for B1004 OBD-II Engine Trouble Code is: Ambient Air Temperature Sensor Circuit Low.