mystikkal_69

iTrader: (2)

i recently acquired a 92z. the damn thing keeps coding code 42. i have switched ecm with the same problem. i'm thinking about trying another ICM module and see if that helps. has anyone else had a persistant code 42. i have cleared the ecm and the code will come back within 5-10 secs once engine is running. (SES Light)

mystikkal_69

iTrader: (2)

i guess no one has had this problem before. if i do fix it i'll be sure to let everyone know.

btw search provided no help.

92'Sleeper

I have had them problems, maybe this will help.
these connection on the ECM are for the 1227730 ECM
(90 - 92 TPI), the (86 - 89) will be the same CKT #'s but different
connections on the ECM (1221765) D4 = 423 & D5 = 424.


1)Clear codes, Idle engine until code appears,
check code to make sure it's still 42.
2)Ignition off, disconnect ALDL connectors, Ignition on,
with an Omhmeter probe CKT. 423 on the ECM to ground (BC8),
It should read less than 500 OHMS. Does it
3) 'NO', Open CKT. 423. Faulty Connection or Faulty Ignition Module.
4) 'YES', probe CKT. 424 (BC7) on ECM with a test light to 12 volts and, (note light).
5)Light 'ON', disconnect Ignition module 4-way connector, light
off now (Faulty Ignition module), Light on, CKT. 424 is shorted
to Ground.
6)Light 'OFF', Attach Ohmmetter again to CKT. 423 and ground,
Probe CKT. 424 again with a test light to 12 volts. (As test light
contacts CKT. 424, Resistance should go from under 500 to over
5,000 OHMS. Does It
7)'No', Dissconnect Dist. 4-way connector. Note OHM meter that is
still connected to CKT. 423 and ground. Resistance should have
gone high (open circuit). Does it. (YES) CKT.424 open,Faulty
connections or faulty Ignition Module. (NO) CKT 423 shorted
to Ground.
8)'YES', reconnect ECM and idle engine until service engine light
comes on. (Light on), code 42 present, faulty ECM. (Light Off),
code 42 Intermittnet, no trouble found. Check harness and
connectors for an intermittent open or short to ground in
CKT. 423 and 424.

wallyZ/28

iTrader: (9)

try making sure your connector forsetting yopur timing is hooked up or look at your knock sensor............could be open or shorted