P17B9 Hupmobile 621 Diagnostic Trouble Code

P17B9 Hupmobile 621 code definition:
P17B9 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Hupmobile 621.

P17B9 Hupmobile 621 is defined as Ignition Coil B Primary/Secondary Circuit Malfunction.This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II tool, or vehicles made since 1996 up to present. 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 P17B9 Hupmobile 621 diagnostic trouble code may include:

Corroded or damaged connector
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Lack of power
Diminished fuel efficiency

Possible Causes :

Faulty IMRC actuator/sensor
A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

Common Misdiagnoses

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
Kick-Down Switch Failed Short Problem
Park/Neutral Postion (PNP) Switch Circuit Engine Torque Signal Circuit Problem

Repair Processes :

Now, clear the codes and test-drive the vehicle to see if the code is reset. Look at the plug wires to make sure they are not burnt or laying on the exhaust. Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness.

Process Tips

Diagnostic trouble code P17B9 Hupmobile 621 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 P17B9 Hupmobile 621.

Fortunately, P17B9 Hupmobile 621 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.