Engine Control System 1A-1 ENGINE Engine Control System CONTENTS Engine Control System . . . . . . . . . . . . . . . . . . . . 1A-2 Precautions on Service . . . . . . . . . . . . . . . . . . . 1A-2 Function and Operation. . . . . . . . . . . . . . . . . . . 1A-4 Component Layout . . . . . . . . . . . . . . . . . . . . . 1A-20 Circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . 1A-25 Strategy-Based Diagnostics . . . . . . . . . . . . . . 1A-31 Functional Check List . . . . . . . . . . . . . . . . . . . 1A-37 Hearing Diagnostic . . . . . . . . . . . . . . . . . . . . . 1A-37 On-Board Diagnostic (OBD) System Check . . 1A-39 Inactive CHECK ENGINE Lamp (MIL) . . . . . .
1A-41 CHECK ENGINE Lamp (MIL) Remains Active 1A-44 Engine Cranks But Will Not Run . . . . . . . . . . . 1A-46 Diagnosis with Tech 2 Scan Tool. . . . . . . . . . . 1A-48 Diagnostic Chart . . . . . . . . . . . . . . . . . . . . . . . 1A-67 DTC11 - No Signal CKP Sensor . . . . . . . . . . . 1A-73 DTC13 - TCV Fault . . . . . . . . . . . . . . . . . . . . . 1A-75 DTC14 - Pump ROM Fault . . . . . . . . . . . . . . . 1A-78 DTC15 - Pump Cam Sensor (NE Sensor) Short Break Fault . . . . . . . . . . . . . . . . . . . . . . 1A-80 DTC16 - No Signal from Pump Cam Sensor (NE Sensor) . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-82 DTC21 - ECT Sensor Fault. . . . . . . . . . . . . . .
1A-84 DCT23 - IAT Sensor Fault. . . . . . . . . . . . . . . . 1A-88 DTC24 - AP Sensor Output Fault . . . . . . . . . . 1A-91 DTC25 - VS Sensor Circuit Fault . . . . . . . . . . 1A-95 DTC31 - Idle Up Volume Fault . . . . . . . . . . . . 1A-98 DTC32 - MAP Sensor Fault . . . . . . . . . . . . . 1A-101 DTC34 - Exhaust Brake Open Wiring Fault . 1A-104 DTC35 - Neutral Switch Signal Fault . . . . . . 1A-106 DTC36 - Clutch Switch Signal Fault (M/T Vehicle only) . . . . . . . . . . . . . . . . . . . . . 1A-108 DTC41 - FT Sensor Circuit High Voltage . . . 1A-110 DTC51 - Atmospheric Pressure Sensor Fault 1A-113 DTC52 - ECM Internal Fault . . . . . . . . . . . . .
1A-114 DTC53 - Engine Driver Unit Fault . . . . . . . . . 1A-116 DTC55 - Pump Unmatched (Difference from ECM Specifications). . . . . . 1A-118 DTC65 - Idle Position Switch Fault . . . . . . . . 1A-120 Symptom Diagnosis Chart . . . . . . . . . . . . . . 1A-122 Hard Starting. . . . . . . . . . . . . . . . . . . . . . . . . 1A-123 Vehicle Speed Variation . . . . . . . . . . . . . . . . 1A-127 Lack Power or Faulty Response . . . . . . . . . . 1A-130 Unstable Idling . . . . . . . . . . . . . . . . . . . . . . . 1A-134 Engine Not Stall . . . . . . . . . . . . . . . . . . . . . . 1A-137 Starter Motor does Not Run . . . . . . . . . . . . . 1A-139 Quick On Start (QOS) System does Not Operate . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . 1A-142 Excessive Black Smoke in Exhaust Gas. . . . 1A-144 Excessive White Smoke in Exhaust Gas . . . 1A-147 Noisy Engine. . . . . . . . . . . . . . . . . . . . . . . . . 1A-149 Nasty Smell. . . . . . . . . . . . . . . . . . . . . . . . . . 1A-152 Poor Fuel Economy. . . . . . . . . . . . . . . . . . . . 1A-155 Excessive Engine Oil Consumption . . . . . . . 1A-159 Large Engine Vibration . . . . . . . . . . . . . . . . . 1A-161 Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-164 Wiring Harness Repair: Shielded Cable. . . . . . 1A-165 Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-165 Installation Procedure . . . .
. . . . . . . . . . . . . . 1A-165 Twisted Leads . . . . . . . . . . . . . . . . . . . . . . . . . 1A-166 Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-166 Installation Procedure . . . . . . . . . . . . . . . . . . 1A-166 Weather-Pack Connector. . . . . . . . . . . . . . . . . 1A-168 Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-168 Installation Procedure . . . . . . . . . . . . . . . . . . 1A-168 Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-169 Com-Pack III. . . . . . . . . . . . . . . . . . . . . . . . . . . 1A-170 General Information . . . . . . . . . . . . . . . . . . . 1A-170 Metri-Pack . . . . . . . . . . . . . . . . . . . . . . . . . . .
. 1A-171 Removal Procedure . . . . . . . . . . . . . . . . . . . 1A-171 Installation Procedure . . . . . . . . . . . . . . . . . . 1A-171 Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . 1A-171