Engine Controls - Unstable Engine Idle After a Cold Soak

Bulletin No. 007/95
Issued 4/5/95
Revised 5/17/95

Category
F

Applicable Model/s
1994 B-2300 M/T

Subject
UNSTABLE IDLE ON COLD START

The revised portion(s) of this bulletin is indicated by an asterisk (*). Replace the original bulletin with this revised copy.

APPLICABLE MODELS/VINS

1994 B-2300 vehicles with a manual transmission and a calibration of 4-49U-R05 or 4-49U-R10.

DESCRIPTION

A customer may complain of rough, rolling (fluctuating) or unsteady idle on initial start-up after an overnight cold soak. A countermeasure PCM (Powertrain Control Module) is available to correct this concern.

REPAIR PROCEDURE

1. Confirm that the vehicle has a calibration code of 4-49U-R05 or 449U-R10 printed on the certification label, located on the driver's side "B" pillar.

^ If the calibration number is one of these codes, proceed to step 2.

^ If the calibration number is not 4-49U-R05 or 4-49U-R10, refer to the workshop manual for troubleshooting instructions.

2. Preform the normal diagnostic procedures (refer to section F of the workshop manual). If any Diagnostics Trouble Codes (DTCs) are found, repair the vehicle as necessary.

3. Confirm that the vehicle's PCM is not a countermeasure part.

NOTE:
Verify that the engineering part no. F4PF-12A650-MA is not on the PCM. The engineering part no. is located just below the bar code label on the PCM connector.

4. Verify the customer complaint after cold soak. If the concern still exists, install the countermeasure PCM.

NOTE:
If the calibration number is 4-49U-R05, replace the Idle Air Control (IAC) motor with a new level part. Refer to the Parts Information below.

5. List the date, dealer number and Service Bulletin number on the "PCM Replacement" label and install the label on to the radiator support.

NOTE:
This label informs technicians of the PCM change if future repairs are necessary.

6. Confirm the repair after cold soak.





PARTS INFORMATION





WARRANTY INFORMATION

(Applies To Verified Customer Complaints On Vehicles Covered Under Normal Warranty. Refer to The SRT Microfiche For Warranty Term Information).

Warranty Type: A
Symptom Code: 03
Damage Code: 9W
Part Number Main Cause: ZZMR 18 888