Diagnostic Trouble Code (Dtc) P0507 Idle Control System Rpm Higher Than Expected - Isuzu 1999 RODEO Workshop Manual

DIAGNOSTIC TROUBLE CODE (DTC) P0507 IDLE CONTROL SYSTEM RPM
Circuit Description
The powertrain control module (PCM) controls engine
idle speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi–directional stepper
motor driven by two coils. The PCM applies current to the
IAC coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
PCM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the PCM detects a condition where too high of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the IAC counts, Diagnostic Trouble
Code P0507 will set, indicating a problem with the idle
control system. DTC P0507 is a type B code.
Conditions for Setting the DTC
f No intrusive tests being run.
f Engine run time is more than 125 seconds.
f No TPS, VSS, ECT, EGR, MAP, IAT, misfire, low
voltage, fuel system or canister purge DTCs are set.
f Barometric pressure is greater than 72.7 kPa.
f Canister purge duty cycle is above 0%.
f Intake air temperature above –40°C (–40°F).
f Engine coolant temperature (ECT) is above 50°C
(122°F).
f Ignition voltage is between 9.5 volts and 16 volts.
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
HIGHER THAN EXPECTED
f The throttle is closed.
f All conditions are met for 10 seconds.
f MAP is less than 60 kPa.
f Engine speed is at least 200 RPM lower than desired
idle, based upon PCM's expectations.
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.
f The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
f The PCM will turn the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.
f A history Diagnostic Trouble Code P0507 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.
f Diagnostic Trouble Code P0507 can be cleared by
using the Scan Tool's "Clear Info" function.
Diagnostic Aids
Check for the following conditions:
f Poor connection at PCM or IAC motor – Inspect
harness connectors
6E1–287
D06RX041
for backed–out terminals,