You’re likely one of the thousands of Isuzu owners who’ve experienced that dreaded Check Engine light flashing on their dashboard. In fact, it’s estimated that over 50% of Isuzu vehicles on the road today have an unresolved issue that’s triggering this warning.
But what does it mean, and how can you uncover the root cause of the problem? Your vehicle’s onboard computer has been tracking the issue, and with the right knowledge, you can tap into its troubleshooting system to identify the specific problem code and take the first step towards getting your Isuzu back on the road.
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Understanding Isuzu OBD I Diagnostics
As you delve into the world of Isuzu OBD I diagnostics, it’s essential to grasp the fundamental principles that govern this system.
You’ll learn that diagnostic trouble codes are displayed through the Check Engine light, which flashes to indicate service codes with a 1/2-second pause between digits and a 2-second pause between codes.
The Control Module (ECM) plays a pivotal role in storing and retrieving these codes.
Understanding code format is essential for diagnosis, as a series of flashes indicate the specific trouble code.
This system is used in vehicles like the Isuzu Trooper, where sensors like the Oxygen sensor and Vehicle Speed Sensor (VSS) provide crucial data to the ECM.
Retrieving and Interpreting Trouble Codes
Your diagnostic journey begins with retrieving and interpreting trouble codes, an essential step in identifying the root cause of your Isuzu vehicle’s issues.
Depending on your vehicle model and fuel delivery type, you can retrieve trouble codes by connecting the diagnostic terminal leads together, grounding the Test terminal of the connector, or using a scan tool.
The Check Engine light will flash to indicate trouble codes, with specific pause patterns between digits and codes.
Understanding the code format is essential for diagnosis, as codes provide information on affected systems and components, such as a sensor or circuit failures, fuel system and ignition issues, and electrical or computer problems related to the Mass Air flow, Vehicle Speed Sensor (VSS), Control Module (ECM), position sensor, or Coolant Temperature.
Isuzu OBD2 Code Categories
You’ve retrieved and interpreted the trouble codes, and now it’s time to categorize them. Isuzu OBD2 codes are grouped into several categories, making it easier to diagnose and repair issues.
Engine and Performance Codes (12-33) diagnose engine, ignition system, and performance-related component problems. Sensor and Circuit Codes (13-25) identify sensor-related faults and circuit issues, such as oxygen sensor problems or coolant temperature sensor circuit faults.
Fuel System and Ignition Codes (41-45) help diagnose fuel system and ignition system issues and related component issues. Electrical and Computer Codes (51-55) diagnose onboard computer and electrical system problems, including PROM, ECM, and EEPROM-related issues.
This categorization helps you pinpoint the problem in your Trooper with a 2.6L or 3.2L engine, whether it’s related to the Vehicle Speed Sensor, Sensor Circuit, Control Module, or Body Fuel Injection.
Most Common Isuzu OBD-II Trouble Codes
| Code | Description |
|---|---|
| P0016 | Inconsistency of crankshaft position sensor’s signal and camshaft |
| P0045 | Excess pressure adjuster |
| P0079 | Exhaust Throttle Control Valve Circuit Low/High Voltage |
| P0087 | Common Rail Pressure Low |
| P0088 | Common Rail Pressure High |
| P0101 | Mass air flow sensor voltage does not match calculated value |
| P0102 | Mass air flow sensor voltage out of range |
| P0116 | Faulty coolant temperature sensor |
| P0201 | Injector circuit malfunction 1 |
| P0202 | Injector circuit malfunction 2 |
| P0203 | Injector circuit malfunction 3 |
| P0204 | Injector circuit malfunction 4 |
| P0217 | Excess motor temperature |
| P0219 | Engine Over Speed Condition |
| P0234 | High Boost Pressure Signal |
| P0299 | Turbocharger Engine Underboost |
| P0335 | Missing crankshaft position sensor signal |
| P0340 | No signal camshaft sensor |
| P0500 | Faulty speed sensor (NQR series), ABS (NPR series) |
| P0601 | Malfunction management unit DWS |
| P1093 | Low pressure in the fuel line |
| P1261 | Open circuit 1 nozzles (1 and 4 cylinders) |
| P1262 | Open circuit 2 nozzles (2 and 3 cylinders) |
| P1361 | TDC Sensor Intermittent Interruption |
| P1380 | ABS Rough Road System Fault |
| P1404 | EGR Valve Stuck Closed |
| P1441 | EVAP System Flow During Non-Purge |
| P1508 | IAC System RPM Low |
| P1509 | IAC System RPM High |
| P1625 | PCM Unexpected Reset |
