Dodge Omni/Horizon/Rampage 1978-1989 Repair Guide

Electronic Fuel Injection

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GENERAL INFORMATION



Single Point Injection

This system is a continuous flow, single point, fully electronically controlled system. A single system electronically monitors the ratio of air to fuel and compares it to an ideal ratio by adjusting it automatically to changing environmental and engine conditions. This system also provides an integrated and pre-programed computer that commands ignition timing, monitors air/fuel ratio and emission control systems. The system also has the ability to update its programing to suite the current engine operating conditions, as required.

The computer has been programmed to monitor various component systems. If a malfunction of a system occurs, a fault code will be stored in the computer. If the problem is repaired or corrects itself, the computer will erase the code after 20 to 40 vehicle starts.

Mult-Point Injection

This fuel injection system is made up of an electronic fuel injection and spark advance control system. The multi-point fuel injection system uses an injector for each cylinder, where the single point fuel injection system has one injector that is positioned in the throttle body assembly. With the multi-point fuel injection system, fuel is pumped to the fuel rail by using an electric fuel pump that is mounted in the fuel tank. The injectors are secured to the fuel rail with lock rings. The rail and the injector assembly is bolted in position with the injectors inserted in the recessed holes of the intake manifold. The fuel rail takes the fuel from the fuel pump and distributes it to the injectors, the injectors then atomize the fuel and spray it into the air entering the individual cylinder combustion chambers.

The computer has been programmed to monitor various component systems. If a malfunction of a system occurs, a fault code will be stored in the computer. If the problem is repaired or corrects itself, the computer will erase the code after 20 to 40 vehicle starts.

READING CODES



The fault codes can be read using diagnostic readout tool C-4805 (or equivalent) or through the Power Loss/Limited lamp. If a fault code appears, perform a careful visual check of all vacuum lines and electrical connections before doing any repairs to the system. The diagnostic read-out tool can be used to check out two other problem modes. They are the circuit actuation test mode and switch test mode. The circuit actuation test mode is used to analyze various systems. The switch test mode is used to test various switch circuits.

Diagnostic Mode
  1. If available, connect Diagnostic Readout Box tool C-4805 or equivalent, to the diagnostic connector located in the engine compartment near the passenger side strut tower.
  2.  
  3. Start the engine if possible. Cycle the transmission selector and the A/C switch if applicable. Shut off the engine. Cycle the ignition switch three times within five seconds.
  4.  


WARNING
When cycling the ignition switch, do not turn to the START position.

  1. Record all the diagnostic codes shown on the readout tool or Power Loss/Limited lamp. Codes can be read from the Power Loss/Limited lamp by counting the number of flashes. For example, a code 35 would be three flashes, a pause, then five more flashes.
  2.  

Code description is as follows:

SINGLE POINT FAULT CODES


CODE 88-Start of the test
 
CODE 11-Engine not cranked since the battery was disconnected
 
CODE 12-Memory Standby power lost
 
CODE 13-MAP sensor pneumatic circuit (Power loss/limited lamp on)
 
CODE 14-MAP sensor electrical circuit (Power loss/limited lamp on)
 
CODE 15-Vehicle speed/distance sensor
 
CODE 16-Loss of battery voltage sense (Power loss/limited lamp on)
 
CODE 17-Engine running too cool (trouble in the cooling system)
 
CODE 21-Oxygen sensor circuit
 
CODE 22-Coolant temperature sensor circuit (Power loss/limited lamp on)
 
CODE 23-Throttle body temperature sensor circuit
 
CODE 24-Throttle position sensor
 
CODE 25-AIS motor driven circuit
 
CODE 26-Peak injection current has not been reached
 
CODE 27-Internal problem in logic module fuel circuit
 
ODE 31-Purge solenoid circuit
 
CODE 33-A/C cutout relay circuit
 
CODE 35-Fan control relay circuit
 
CODE 37-Shift indicator light circuit
 
CODE 41-Charging system excess or no field circuit
 
CODE 42-Auto shutdown relay driver
 
CODE 43-Spark interface circuit
 
CODE 44-Battery temperature is out of range
 
CODE 46-Battery voltage is too high (Power loss/limited lamp on)
 
CODE 47-Battery voltage is too low
 
CODE 51-Oxygen feedback system stuck in the lean position
 
CODE 52-Oxygen feedback system stuck in the rich position
 
CODE 53-Internal logic module problem
 
CODE 55-End of message
 

MULTI-POINT FAULT CODES


CODE 88-Start of the test
 
CODE 11-Engine not cranked since the battery was disconnected
 
CODE 12-Memory standby power lost
 
CODE 13-MAP sensor pneumatic circuit (Power loss/limited lamp on)
 
CODE 14-MAP sensor electrical circuit (Power loss/limited lamp on)
 
CODE 15-Vehicle speed/distance sensor
 
CODE 16-Loss of battery voltage sense (Power loss/limited lamp on)
 
CODE 17-Engine running too cool (trouble in the cooling system)
 
CODE 21-Oxygen sensor circuit
 
CODE 22-Coolant temperature sensor circuit (Power loss/limited lamp on)
 
CODE 23-Charge temperature sensor circuit (Power loss/limited lamp on)
 
CODE 24-Throttle position sensor
 
CODE 25-AIS motor driven circuit
 
CODE 26-Number one injector circuit
 
CODE 27-Number two injector circuit
 
CODE 31-Purge solenoid circuit
 
CODE 33-A/C cutout relay circuit
 
CODE 34-EGR solenoid circuit
 
CODE 35-Fan control relay circuit
 
CODE 36-Wastegate solenoid circuit (Power loss/limited lamp on)
 
CODE 37-Barometric read solenoid circuit
 
CODE 41-Charging system excess or no field circuit
 
CODE 42-Auto shutdown relay driver
 
CODE 43-Spark interface circuit
 
CODE 44-Battery temperature is out of range
 
CODE 45-Overboost shut-off circuit
 
CODE 46-Battery voltage is too high (Power loss/limited lamp on)
 
CODE 47-Battery voltage is too low
 
CODE 51-Oxygen feedback system stuck in the lean position
 
CODE 52-Oxygen feedback system stuck in the rich position
 
CODE 53-Internal logic module problem
 
CODE 54-Distributor sync pick-up circuit (Power loss/limited lamp on)
 
CODE 55-End of message
 

Circuit Actuation Testing
  1. Put the system into diagnostic mode testing and wait for code 55 to appear on the test screen. Press the ATM button on the diagnostic tool to activate the display.
  2.  
  3. If a specific ATM test is desired, hold the ATM button down until the desired test code appears.
  4.  
  5. The computer will continue to turn the selected circuit on and off for as long as five minutes or until the ATM button is pressed again or if the ignition switch is turned OFF .
  6.  
  7. If the ATM button is not pressed again, the computer will continue cycling the selected circuit for five minutes and then shut the system off. Turning the ignition switch OFF will also shut the test mode off.
  8.  

Code description is as follows:



CODE 01-Spark Activation, once every two seconds
 
CODE 02-Injector Activation, once every two seconds
 
CODE 03-Automatic Idle Speed System (AIS) Activation, one step open/one step closed every four seconds
 
CODE 04-Radiator Fan Relay, once every two seconds
 
CODE 05-A/C Wide Open Throttle Cut Out Relay, once every two seconds
 
CODE 06-Automatic Shut Down Relay (ASD) Activation, once every two seconds
 
CODE 07-Purge Solenoid Activation, one toggle every two seconds
 

Switch Testing Mode
  1. Put the system into diagnostic mode testing and wait for code 55 to appear on the test screen.
  2.  
  3. After code 55 appears, actuate the following component switches. The digital display must change its numbers when the switch is activated and released:

    Brake pedal
     
    Gear shift selector
     
    A/C switch
     
    Blower switch
     
    Speed sensor
     

  4.  

CLEARING CODES



The computer will automatically erase the code(s) after 20 to 40 vehicle starts after the problem has been repaired. The code(s) may also be erased manually by disconnecting the negative battery cable for 30 seconds.

 
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