Diagnostic Procedures
- Perform On-Board Diagnostic II (OBD-II) system check. See
SELF-DIAGNOSTICS - INTRODUCTION article. After performing OBD system check, go to next step.
- With ignition on and engine off, review and record FAILURE RECORDS data on scan tool, then clear the DTCs. Operate vehicle within conditions noted in FAILURE RECORDS data. Monitor specified DTC information. If scan tool indicates DTC P0106 RAN AND PASSED, go to next step. If scan tool does not indicate DTC P0106 RAN AND PASSED, go to step 4.
- Check for the following conditions: vacuum hoses disconnected, damaged or incorrectly routed, intake manifold vacuum leaks, throttle body leaks, and EGR valve flange and pipe leaks. Repair as necessary. Retest system. If no problem is found, see DIAGNOSTIC AIDS .
- Disconnect MAP sensor connector and observe MAP value displayed on scan tool. Normal reading would show zero volts and 10.3 kPa. If reading is normal, go to step 6. If reading is not normal, go to next step.
- Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Using a DVOM, check for short to voltage in MAP sensor input circuit between MAP sensor connector and appropriate PCM harness connector terminal. See Figure and Fig 1
. If voltage is indicated, locate and repair as necessary. If no voltage is indicated, go to step 12.
Courtesy of ISUZU MOTOR CO.
- Turn ignition off. Disconnect PCM harness connectors. Using a DVOM, check MAP sensor input circuit (Gray wire) between MAP sensor connector and appropriate PCM harness connector terminal for open circuit or short to ground. Repair as necessary. If no problem was found, go to next step.
- Connect PCM harness connectors. Turn ignition on. Check MAP sensor connector 5-volt reference terminal (Red wire) for voltage. If reading indicates about 5 volts, go to next step. If reading does not indicate about 5 volts, locate and repair open or shorted condition in 5-volt reference circuit.
- Turn ignition off. Using a fused jumper wire, connect Red and Green wires together at MAP sensor connector. Turn ignition on. Observe MAP value displayed on scan tool. If reading is about 5 volts and 104 kPa, go to next step. If reading is not as specified, go to step 12.
- Turn ignition off. Disconnect PCM harness connectors. Check continuity of MAP sensor ground circuit between MAP sensor connector and White 32-pin PCM harness connector terminal D8 (Green wire). If continuity does not exist, repair MAP sensor ground circuit as necessary. If continuity exists, go to next step.
- Connect PCM harness connectors. Connect DVOM positive lead to MAP sensor connector Red wire (5-volt reference), and negative lead to MAP sensor connector Green wire (ground). Turn ignition on. If reading indicates about 5 volts, go to next step. If reading does not indicate about 5 volts, go to step 12.
- Replace MAP sensor. Retest system.
- Replace and reprogram PCM using required equipment. See PROGRAMMING . Retest system.