Possible causes
– Trailer towing may set code
– Check transmission fluid level
– Internal transmission fault
– Check transmission fluid level
– Internal transmission fault
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1870 ISUZU Description
Transmission is in 4th gear with Torque Converter Clutch (TCC) engaged and the Engine Control Moduel (ECM) has detected excessive slippage when comparing the input shaft speed to the output shaft speed
ISUZU Technical Service Bulletins for P1870 code
2006 ISUZU I-280 POWER TRAIN
2006 ISUZU I-350 POWER TRAIN
2003 ISUZU ASCENDER POWER TRAIN
2004 ISUZU ASCENDER POWER TRAIN
2005 ISUZU ASCENDER POWER TRAIN
2006 ISUZU ASCENDER POWER TRAIN
1997 ISUZU HOMBRE POWER TRAIN:AUTOMATIC TRANSMISSION
1998 ISUZU HOMBRE POWER TRAIN:AUTOMATIC TRANSMISSION
1999 ISUZU HOMBRE POWER TRAIN:AUTOMATIC TRANSMISSION
2000 ISUZU HOMBRE POWER TRAIN:AUTOMATIC TRANSMISSION