| MAT sensor reads 392 |
Subject: MAT sensor reads 392 by joeld on 2008/1/6 3:03:41 Hey guys, need a little help on this one. 1989 auto. with L98. I've had car for 10 years. I use a Actron scanner, older model but seems to work fine on all my cars. Car runs very well with no problems. Only thing is when I scan it the MAT always reads 392 degrees. Same reading cold or hot. Today I finally decided to start trying to find out why. Replaced MAT sensor in plenum, no change. Disconnected harness from sensor, no change. Discinnected extension (FSM calls this a jumper) from main harness, no change. Checked voltage on tan wire CKT 472 for the 5 volts as per FSM and OK there. If I read the diagram correctly this sensor CKT 452 black wire at ECM shares the ground with CTS and TPS. No problem with these sensors, so I assume the ground is good at ECM. Also no codes at all, I would think a 25 should have been set(high temp). Car is bone stock. Only other thing is that car does have a replacement ECM. Label says :Remn. by GM Service Part# 16198445. Prom says APKC 1304. All this should be the correct ECM and PROM unless I'm wrong. Any thoughts? |
