Powertrain Controls - ECM/PCM

Diagnostic Trouble Code 36:

ISC Actuator Circuit:

CIRCUIT DESCRIPTION
The control module grounds CKT 534 when ECT is within range to enable the solenoid, allowing vacuum to retract the idle speed control actuator and lower the idle to controlled idle specification

DTC 36 WILL SET WHEN
^ Closed loop.
^ Idle speed actuator is enabled.
^ TP sensor signal voltage stored.
^ Idle speed actuator is disabled.
^ TP sensor signal voltage stored.
^ Difference between the two TP sensor voltage is less than 0.04 volts for more than 1 second.
^ Test is run once per ignition cycle.

ACTION TAKEN (PCM WILL DEFAULT TO)
None. (Warm idle speed will be higher than normal when idle speed control actuator system is inop.)

DTC 36 WILL CLEAR WHEN
Conditions for fault are no longer present and Tech 1 "clear DTCs" function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and battery feed voltage is removed for 10 seconds.

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

1. Checks to see if a vacuum source is present.

2. Checks to see if idle speed control actuator solenoid is commanded "ON."

3. Checks for power to the solenoid, the ground circuit, the connections at the idle speed control actuator solenoid and the solenoid itself.

4. Checks for open or grounded CKT 539.

5. Checks for open CKT 543 or faulty control module.

DIAGNOSTIC AIDS
If BARO is below 68 kPa, a 96 second reset will result.

If DTC 36 sets, a DTC 35 will usually also set. Repair the DTC 36 first, clear DTCs and recheck for DTCs.

If IAC counts are at 0, the idle speed control actuator will disengage and raise idle speed.