Engine Controls - Lack of Engine Power

Classification:
EC03-004

Reference:
NTB03-023

Date:
March 15, 2003

2002-2003 MAXIMA & ALTIMA: LACK OF POWER

APPLIED VEHICLES:
2002-2003 Maxima (A33)
2002-2003 Altima (L31) only with V6 (VQ35) engine.

IF YOU CONFIRM:
An Applied Vehicle has a slight lack of power during acceleration,

DETERMINE IF:
Premium fuel is being used in the vehicle.

ACTIONS:
If premium fuel is being used;

^ Check the ECM Part Number. You will do this by performing step 2 and 3 in the Service Procedure.

^ Replace Mass Airflow Sensor (if needed; see Chart A-2).

^ Perform ECM Reprogramming. This is required if the ECM Part Number (PIN) in the vehicle matches one of those listed under "Current ECM P/N" in Chart A-1 or A-2.





PARTS INFORMATION

CLAIMS INFORMATION





Submit a Primary Failed Part (PP) line claim using the claims coding shown.

IMPORTANT:
The purpose of "ACTIONS" (above) is to give you a quick idea of the work you will be performing. You MUST closely follow the entire Service Procedure as it contains information that is essential to successfully completing this repair.

SERVICE PROCEDURE

1. Determine if premium fuel is being used in the vehicle:

^ If premium fuel is being used, proceed to step 2.

^ If premium fuel is not being used:

a. Tell the customer that premium fuel should be used for improved performance.

b. Ask the customer to use-up their regular fuel, then fill the tank with premium.

c. Request the customer drive the vehicle with premium fuel for a few days and return to the dealer if they feel there is still a slight lack of power on acceleration.

2. Determine the vehicle's ECM Part Number. The ECM P/N is found by using CONSULT-II. Go to ECM P/N Selection.





3. Compare the vehicle's ECM P/N to those shown under Current ECM P/N in Charts A-1 and A-2.

A. Check Chart A-1: If the ECM P/N in the vehicle matches one of those listed under "Current ECM P/N":

^ Perform ECM Reprogramming, step 4.

B. Check Chart A-2: If the ECM P/N in the vehicle matches one of those listed under "Current ECM P/N":

^ Replace the Mass Airflow Sensor (see Parts Information). Refer to the applicable Service Manual (ESM), section EC, for replacement procedures.

^ Perform ECM Reprogramming, step 4.

C. If the ECM P/N in the vehicle does not match one of those listed under "Current ECM P/N" in Chart A-1 or A-2:

^ This bulletin does not apply. Use the appropriate Electronic Service Manual (ESM) to further diagnose and repair the incident.

4. Reprogram the ECM.

IMPORTANT NOTES:

^ This I.D. code process is different from the "typical" ECM Reprogramming procedures now in use.

^ Do NOT use "Attachment A" (from other bulletins) for the reprogramming required in this bulletin.

Obtaining Special ECM Reprogramming Data Using an ID Code:

^ Use these steps if you are familiar with this Special ECM reprogramming procedure.





1. Click on the Keypad button (see Figure 1).





2. Use the digit keys on the KeyPad (see Figure 2) to enter the correct ECM ID Code from Chart A-1 or A-2.

3. Then click the "Continue" button on the keypad.





4. Click the "Continue" button on the ECM Data Reprogramming screen (see Figure 3) to proceed to CONSULT-II setup.

5. Continue the reprogramming procedure.