Engine Controls - Surge/Rolling Idle/No DTC's Present
TSB 09-16-608/24/09
ROLLING IDLE AND/OR ENGINE SURGE WITH NO DIAGNOSTIC TROUBLE CODES (DTC) PRESENT
FORD:
2008-2009 Focus
ISSUE
Some 2008-2009 Focus vehicles may exhibit a rolling idle (400-1000 RPM) and/or engine surging condition with no diagnostic trouble codes (DTC) present. This may be due to an erratic Exhaust Gas Recirculation (EGR) stepper motor signal commanded from the Powertrain Control Module (PCM).
ACTION
Follow the service procedure steps to correct the condition.
SERVICE PROCEDURE
1. Verify proper EGR signal is being commanded from the PCM.
a. Install VMM 50 Amp inductive current probe (Rotunda Part Number 164-R9530) into the IDS and set the oscilloscope to the following settings.
(1) Channel 4.
(2) Vertical Scale 500 mA.
(3) Time Base 500 mS.
(4) Trigger CH4, Rising Edge, One Shot.
(5) Filter 1.3 kHz.
b. Place the IDS current clamp around circuits CE101, CE102, CE103, and CE104 one at a time and capture the EGR stepper motor current at vehicle startup. A single waveform will be captured at startup, and the scope will automatically stop. Set the scope to "run" after each waveform has been collected.
A normal EGRMC waveform is 50/50 duty cycle for 16 cycles. Reference (Figure 1) for a normal signal, and (Figures 2-5) for defective PCM EGR stepper motor signals.
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage
IMPORTANT:
Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
OPERATION DESCRIPTION TIME
091606A 2008-2009 Focus: Perform 1.0 Hr.
The Diagnosis Outlined In
the Service Procedure
Includes Time To Replace
The PCM If Necessary (Do
Not Use With Any Other
Labor Operations)
DEALER CODING
CONDITION
BASIC PART NO. CODE
12A650 42
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