Majestic L6-4.0L (1990)
Engine Control Module: All Technical Service Bulletins
ECU - Unnecessary Replacement Due to DTC 29
ENGINE MANAGEMENT ECU - VCM FUEL FAIL CODE 29
90 - 91 My SEDANS Date: APRIL, 1991
Do NOT REPLACE ECU BEFORE TESTING
Unnecessary replacement of Engine Management ECU due to fuel fail code 29.
Fuel Fail Code 29 may be activated during engine start up when battery voltage is low. This does not necessarily indicate a faulty ECU.
If Fuel Fail code 29 is displayed, JDS will state "Lucas EMS ECU Fault". DO NOT replace the ECU and perform the following:
Check battery voltage and connections. Charge the battery if necessary (refer to Technical Bulletin section 86, No. 68 and 88).
Erase code 29 using by disconnecting the battery.
Check the connections to the ECU.
Start the engine several times. If code 29 does not recur, no further action is necessary. If code 29 does recur, proceed as follows:
Replace the ECU.
List "code 29" and "Repeatable Fault" on an ECU fault description label (S 41) and attach it to the old ECU before returning it to your Zone Parts
Repair Operation Number:
18.30.01 (Replace ECU)