C2598 Allard J2 Diagnostic Trouble Code

C2598 Allard J2 code definition:
C2598 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code for Allard J2.

C2598 Allard J2 is defined as Cylinder 3 Injector Circuit Malfunction. This code means the PCM (powertrain control module, also known as ECM or engine control) has detected a problem in the injector or its wiring, or in injector circuit for cylinder 3. There are two wires dedicated for each coil; one is battery feed which usually comes from the distribution center, and the other one for the coil driver circuit from the PCM. The PCM grounds or ungrounds the circuit to activate or deactivate the coil.

Symptoms

Symptoms of a C2598 Allard J2 diagnostic trouble code may include:

Poor fuel economy
Possible spark knock (detonation / pre-ignition)
Misfire
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.

Common Misdiagnoses

IC Circuit High Voltage Problem
Control Module Throttle Actuator Position Performance Problem
Air Conditioning (A/C) Clutch Feedback Circuit High Voltage Problem
Cruise Vehicle Speed/Set Speed Difference Too High Problem
PCM Stack Overrun Problem

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. 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. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors.

Process Tips

Diagnostic trouble code C2598 Allard J2 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 C2598 Allard J2.

Fortunately, C2598 Allard J2 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.