DDEC III/IV Single ECM Troubleshooting – Section 10.3 Erratic Performance and No Codes

Section 10.3
Erratic Performance and No Codes

The following troubleshooting chart resolves erratic performance and no codes displayed. For troubleshooting procedures, refer to the appropriate engine service manual.‪

Section 10.3.1
Erratic Performance and No Codes

Check the following symptoms to determine possible fault, listed in Table "Troubleshooting Erratic Performance and No Code" .‪


Possible Fault

Cannot get full power.‪

Plugged fuel filters. Hose not connected to Turbo Boost Sensor. Verify injector calibration(s) are correct.‪

Cannot get full throttle.‪

Mis-calibrated Throttle Position Sensor.‪

Runs rough; misses and occasionally stalls.‪

Improper gapping of Timing Reference and Synchronous Reference Sensor. Fuel leaks. Loose battery power, ignition or ground wires Injector failure. Vehicle speed sensor failure. Injector harness failure.‪

Engine idles high after warm-up or hangs.‪

Incorrect calibration of Throttle Position Sensor. TPS linkage or pedal problem. VSG signal wire shorted to voltage source.‪

Low road speed.‪

Determine road speed specifications for vehicle manufacturer data. If road speed is less than specified and all mechanical checks are correct, then cruise control calibration is suspected.‪

Vehicle surges or bucks.‪

VSS may be supplying incorrect data to the ECM.‪

Table 1. Troubleshooting Erratic Performance and No Code

DDEC III/IV Single ECM Troubleshooting Guide - 6SE497
Generated on 10-13-2008

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