Applicable Model(s)/VINS

All 1999 Miatas with VINs lower than JM1NB35** X0 122015

Description

During the auto cruise control function, any of the following problems may occur:

• Vehicle speed fluctuation
• Cruising speed is 5-7 m.p.h. higher than the set speed.
• Coast function (deceleration system) becomes inoperative.

These symptoms may be caused by a transistor malfunction inside the cruise control unit. A modified part with a heavy duty transistor is available to resolve this concern.

Cutomers complaining of this concern should have their vehicle repaired using the following procedure.

Repair Procedure

1. Verify customer complaint.
2. Measure the battery voltage and note it on the repair order.
3. Turn the ignition switch ON, then turn the cruise control main switch ON.
4. Measure voltage of cruise control module at terminal 'A' (G/Y wire). Refer to Section 01-20 of the Workshop Manual.
   • If voltage at terminal 'A' is at least 1.0V lower than the battery voltage measured in Step 2, replace cruise control module with modified part.
   • If voltage difference between battery and terminal 'A' is within 1.0V, cruise control unit has no problem.
5. Verify repair.

Parts Information

Warranty Information

Note

• This informatoin applies to verified customer complains on vehicles covered under normal warranty. Refer to the SRT microfiche for warranty term informaton.

Warranty Type Code:	A
Symptom Code:	54
Damage Code:	9W
Part No. Of Main Cause	NC12 66 320
Quantity:	1
Operation No./ Labor Hour:	T0804XRX / 0.5

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