Diagnostic Trouble Code (Dtc) P1635 5 Volt Reference Voltage Circuit Malfunction - Isuzu 1999 RODEO Workshop Manual

6E1–350 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DIAGNOSTIC TROUBLE CODE (DTC) P1635 5 VOLT REFERENCE VOLTAGE
Circuit Description
The Powertrain Control Module (PCM) monitors the 5 volt
reference signal when the Ignition is ON. If the PCM
senses the 5 volt reference signal circuit is above 5.12
volts or below 4.88 volts, then DTC P1635 will set. DTC
P1635 is a type A code.
Conditions for Setting the DTC
f Ignition voltage is greater than 6.3 volts.
f Engine is running.
The above mentioned conditions are met and one of the
following two conditions are met for 5 seconds within a 10
second test sample:
f PCM senses the 5 volt reference signal circuit is above
5.12 volts.
OR
f PCM senses the 5 volt reference signal circuit is below
4.88 volts.
CIRCUIT MALFUNCTION
Action Taken When the DTC Sets
f The PCM will illuminate the Malfunction Indicator Lamp
(MIL) the first time the fault is detected.
f The PCM will store the conditions that were present
when the DTC was set as Freeze Frame and in Failure
Records.
Conditions for Clearing the MIL/DTC
f The PCM will turn OFF the MIL on the third consecutive
trip without a reported failure.
f A History DTC will clear after 40 consecutive trips
without a reported failure.
f The DTC can be cleared using the Scan Tool's "Clear
Info" function.
Diagnostic Aids
Poor connections, or a damaged harness – Inspect the
harness connectors for: backed–out terminals, improper
mating or damaged terminals. Also, check for open
circuits, shorts to ground, and shorts to voltage.
D06RX062