Inspection Procedure
INSPECTION PROCEDURE FOR DTC 121. CHECK RESISTANCE OF EACH PICKUP COIL IN DISTRIBUTOR.
- Disconnect distributor connector.
- Measure resistance between each terminal shown in the following table.
"Cold" resistance value:
'G1' - G- = 125 - 200 Ohms
'G2' - G- = 125 - 200 Ohms
'NE' - G- = 155 - 250 Ohms
{"Cold" is from -10°C (14°F) to 50°C (122°F)}
"Hot" resistance value:
'G1' - G- = 160 - 235 Ohms
'G2' - G- = 160 - 235 Ohms
'NE' - G- = 190 - 290 Ohms
{"Hot" is from 50°C (122°F) to 100°C (212°F)}
^ If OK proceed to step 2.
^ If not OK replace distributor.
2. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR BETWEEN ENGINE CONTROL MODULE (ECM) AND DISTRIBUTOR.
^ If OK proceed to step 3.
^ If not OK repair or replace harness or connector.
3. CHECK AIR GAP.
- Remove distributor cap & rotor.
Camshaft Position Sensors (G1, G2):
- Using the special service tool (SST# 09240-00020) for 'G1' and 'G2' pickups and a thickness gauge for the 'NE' pickup, measure the air gap between the signal rotor and pickup coil projection.
Air gap: 0.2 - 0.5 mm (0.008 - 0.020 in)
^ If OK check and replace ECM
^ If not OK replace distributor.