Powertrain Codes

P0232

Technical Definition:

Fuel Pump Secondary Circuit High

Trouble Code: P0232
Address: 0x0232
System: Powertrain
Subsystem: Fuel and Air Metering
Technical Description:

The fuel pump is powered by the fuel pump relay. When the PCM (powertrain control module) activates the fuel pump relay, voltage is supplied to the fuel pump and it pressurizes the fuel system. Some vehicles have a feedback on the fuel pump supply circuit. This is simply a circuit spliced into the voltage feed to the fuel pump. The splice is usually located close to the PCM.

Possible Causes:
  • Bad FP relay
  • Short to voltage on FP voltage supply circuit or feedback circuit
  • Short to ground on PCM
  • FP relay control circuit PCM
  • FP relay control driver shorted to ground internally

Possible Symptoms:
  • MIL (malfunction indicator lamp) illumination
  • Fuel pump runs with key off
  • Small amount of voltage present on FP (fuel pump) voltage supply circuit due to short

Fuel Pump Secondary Circuit High

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Blown Fuel Pump fuse
– Open Fuel Pump Monitor Circuit
– Faulty Fuel Pump Relay
– Damaged Engine Control Module (ECM)

Specific Makes:

P0233

Technical Definition:

Fuel Pump Secondary Circuit Intermittent

Trouble Code: P0233
Address: 0x0233
System: Powertrain
Subsystem: Fuel and Air Metering
Technical Description:

Possible Causes:

Possible Symptoms:

Throttle Position Sensor 2 Circuit Low

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Throttle position sensor
– Throttle position sensor harness is open or shorted
– Throttle position sensor poor electrical connection

Specific Makes:

– No throttle response

P0234

Technical Definition:

Turbocharger / Supercharger Overboost Condition

Trouble Code: P0234
Address: 0x0234
System: Powertrain
Subsystem: Fuel and Air Metering
Technical Description:

This diagnostic trouble code (DTC) is a generic powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may be slightly different depending on the model.

Trouble code P0234 indicates the powertrain control module (PCM) senses a dangerously high boost pressure from the engine’s forced induction system. Levels of boost in excess of recommended levels can compromise the structural integrity of the engine.

Possible Causes:
  • In lieu of further trouble codes associated with the overboost condition it would be safe to say the problem is mechanical. The operation of the wastegate is the most probable.
  • The wastegate is either stuck closed causing the turbo to spin higher than normal, thus causing the overboost.
  • The rod from the wastegate actuator to the wastegate on the turbo is bent.
  • A hose came off the wastegate or boost controller.
  • A supply house to the boost controller or from the controller to the wastegate is clogged.
  • Dodge trucks with a Cummins diesel have a peculiar problem. They run fine but the check engine light comes on and sets code P0234 at an idle, yet the light goes out several minutes later at cruise speeds. The digital boost control gauge is connected into the MAP sensor which has an intermittent fault at idle yet does not set a code. Replacement of the MAP sensor corrects this.

Possible Symptoms:
  • The service engine soon or check engine light will illuminate.
  • You will experience a loss of power.
  • The engine may show signs of overheating.
  • The transmission may show signs of overheating and harsh shifting.
  • Additional codes associated with the condition set by P0234 may be present to help identify the cause. Codes are available for all electrical components utilized by the engine management computer for the control of boost levels.
  • The engine may display signs of pre-ignition in the form of knocking.
  • The engine may display ignition misfiring.

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

Specific Makes:

P0230

Technical Definition:

Fuel Pump Primary Circuit

Trouble Code: P0230
Address: 0x0230
System: Powertrain
Subsystem: Fuel and Air Metering
Technical Description:

The fuel pump is activated by a PCM-controlled relay. Just as the name implies, a “relay” permits the transmittal of higher amperage current to the fuel pump without that current having to travel through the PCM (Powertrain Control Module).

Possible Causes:
  • Short to ground on control circuit
  • Fuel pump control circuit open
  • Short to battery voltage on control circuit
  • Harness chafing causing one of above conditions
  • Bad relay
  • Bad PCM

Possible Symptoms:
  • MIL (malfunction indicator lamp) illumination
  • No start condition
  • No fuel pump operation
  • Fuel pump runs all the time with ignition on

Fuel Pump Primary Circuit Malfunction

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Blown Fuel Pump fuse
– Open Fuel Pump Monitor Circuit
– Faulty Fuel Pump Relay
– Damaged ECM

Specific Makes:

P0231

Technical Definition:

Fuel Pump Secondary Circuit Low

Trouble Code: P0231
Address: 0x0231
System: Powertrain
Subsystem: Fuel and Air Metering
Technical Description:

Possible Causes:

Possible Symptoms:

Fuel Pump Secondary Circuit Low

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Blown Fuel Pump fuse
– Open Fuel Pump Monitor Circuit
– Faulty Fuel Pump Relay
– Damaged Engine Control Module (ECM)

Specific Makes: